M103 - oil/coolant leak front of engine
 

UPDATE! It was the very short coolant hose that runs from the thermostat housing to the head that was leaking. Put in a new clamp and it has stopped leaking! Glad it was nothing serious! Thanks!

FINALLY a problem to report on my 88' 300SEL after it being a boringly trouble free car.

I have read about this and have seen several threads about the front timing cover being an issue on these cars. I was under my car the other day (after not driving it for 2 weeks, as I was out of town) and noticed coolant drips on the lower front of the oil pan. Concerned, I wiped under there and its a oil/coolant mix. Its green, but it feels more like oil once on the finger. Does this sound like its the timing chain cover or the headgasket? There is NO coolant in the oil, nor oil in the coolant and it never overheats. Its so small of a leak that the oil level is almost always full, even after 4000 miles and the coolant level has stayed the same over several months. I did have to add coolant back in the winter, but when temperatures warmed in the spring and summer, it never went down again.

Here are some photos I snapped about 2 weeks ago... still like this.

If it is the front timing chain cover, is this a difficult repair and how much would a typical shop charge on average to replace this seal? I dont know... maybe its time to get another car.

http://i39.photobucket.com/albums/e1...photos/071.jpg
http://i39.photobucket.com/albums/e1...photos/066.jpg
http://i39.photobucket.com/albums/e1...photos/067.jpg

thanks for any advice!

Coolant does feel a little oily, it does not mean it is mixed with oil...

The best thing to do now is to clean the engine really good, and try to pinpoint the exact location of the leak (s). other than that, you might start an expensive repair that you might not need.....

From the picture, it does not look like the timing cover. it is not the water pump because it is on the other side of the engine.....

it is either something simple like a coolant hose/ pipe squirting coolant everywhere, or more serious such as an engine freeze plug, or leaky headgasket..., but again, i am just guessing here. the starting point is to clean the engine, raise the car until you find the source (you might use a mirror for the hard to see areas), and go from there...

or you could drop it off at your indy :D

Good luck !!

Edit: WOW, i just noticed you have 2000ish posts, so you probably know what I've said already.,,,,ignore my post

clean up the area and then run the engine and see where it comes from

Many higher mileage M103's I see have this problem.
Head gasket starting to deteriorate.

Thanks for the replies... I will try to clean it and check it, or get a shop to.

Headgasket? Oh my! :eek: I was hoping I would not have that problem quite yet with this car. :( I cant afford to have the headgasket replaced at this time. Not now. I just spent a small fortune on my LS400. :rolleyes:

Is 157K high miles for these M103 engines?

I had a 380SE with nearly 280K and it was still fine.

If its the headgasket, it will have to find it a new home... one where someone knows how to or can afford to fix it. :(

Not sure of these are any better, but here are more I took today. I finally drove the car after it had been setting for about 2 weeks, checked oil and coolant... still full. hmmm.

Yeah, it all appears to be on the right side of the oil pan.

Left side of pan is dry...
http://i39.photobucket.com/albums/e1...otos/001-1.jpg

more of the right side...
http://i39.photobucket.com/albums/e1...otos/003-1.jpg
http://i39.photobucket.com/albums/e1...photos/004.jpg
http://i39.photobucket.com/albums/e1...photos/005.jpg
http://i39.photobucket.com/albums/e1...otos/011-1.jpg

I just completed a head-gasket R&R on my 1990 300SEL. I had a similar situation. I had both oil and coolant seeping from the head gasket on the passenger side of the car. Mine was more toward the rear of the block. No oil and coolant mixed in the engine, and I never had an overheating problem. If it is a head gasket leak you should be able to look up, from under the car, on that side of the engine at where the block meets the head. In my case there was a thin trail of oil and coolant and white effervescence clearly leaving the leaking area of the headgasket.

Thanks. Was that a pain in the neck to replace?

I dont have coolant in oil or visa-versa and it never overheats... also I have not even noticed a drop in the coolant level or oil level, except back in the winter months, I had to add coolant, but it didnt drop in the summer months.

Looks to me like the timing cover is leaking oil slowly. Clean it all up because otherwise it will be impossible on this car.

As for coolant, look at the freeze plugs on the block.

158k is not a lot of miles on a 103...but if the head gasket is still original its probably getting close by now.

Take a close look at the block coolant drain plug on the right side of the engine to make sure it isn't leaking. You may want to put a wrench on it and verify that it's tight.

Unfortunately, from your various pictures it appears that the head gasket is leaking. Our daughter's 1991 300CE's engine had a similar appearance when the head gasket was shot. After a local indie replaced the head gasket the engine was bone-dry. As I recall the bill for parts and labor was $2,500 ... most of the cost being labor. An experienced DIY'er can do the job very inexpensively with the proper tools. Best to use a lift for pulling the head.

The head gasket job wasn’t as bad as I thought it would be; but it was a lot of work.
This is what I did; drain coolant, remove spark plugs, set engine at TDC on #1 piston, remove exhaust manifold at the head, remove intake manifold at the head, remove fan, serp belt, distributor cap and rotor, valve cover, upper timing chain cover, cam gear, Timing chain tensioner, upper timing chain rail pin, removed head. Once off I cleaned the surface of the head and block with a pneumatic die grinder and those 3M 3” disk pads that screw lock into place. Then set the gasket in place and torque to spec. I also changed out my water pump at the same time and that added quite a bit of time to the project. The water pump to me was worse then removing the head. I had about $450 in parts and supplies in the whole job. The job went smooth except for a half dozen bolts that really slowed me down.
A couple observations; I think you really need two people to remove and set the cylinder head properly and safely, unless you have a very extensive tool box already you need to have special/odd/improvised, tools to remove the fan, timing chain tensioner, timing chain upper rail pin, and head bolts. I also helped to have a wobble head 3/8 drive extension to get at those water pump bolts. Oh; and if you replace the water pump, be sure to use a little grease or the same sealer you use for the timing chain cover to hold the big “O” ring seal in place while you reassemble. If you don’t, the gasket can go in crooked and you will have to take it all apart again. Don’t ask me why I know

lol. Not at all. I am an idiot when it comes to cars. ;)

Thanks outofspec for that detailed explanation - definitely sounds like something too much for me to tackle. :(

Ph2cho - thanks. It does feel greasy, but its green too... the little drips from the pan are green. :(

Ferdman - thanks... it hurts to hear it could likely be the headgasket. Unfortunately, I cant afford such a repair.... not now. My uncle in South Carolina found a guy to replace his headgasket for $1200 on his 300SE (1992). A little mechanic from Korea did the work. Other places were quoting him $2500-3000. He also did his evaporator core for $700.

I would probably be better off trying to sell it or trade it. I prefer to trade it, so I wont have to pay taxes. I didnt see the leak until now and I had hoped that it (headgasket) had already been replaced since its not using any oil now. When I bought the car, it was from a broker in Atlanta. The guy drove the car up here to Tennessee. I looked under it and it looked clean, but I bet it was leaking then and they had cleaned up the engine to dump it... on me of course. :(
I should not be suprised though... I have never had any luck with cars... aways buy something that soon needs major work. People always taking advantage of my trusting soul. I just took his word for it and paid him $2600.

I dont know what the car is worth to someone now or how long it will be OK like this if it is the HG. The cars body and interior are nice, everything works (A/C is only cool) and the transmission is good, so its still a good car in that aspect.

Has anyone ever heard of or tried that Lucas headgasket stop leak? Its like $50, but says it WILL stop your leaky headgasket... but not sure what kind of # it would do on your radiator or heater core.

Oh well... sounds like I have some decisions to make. :o I just missed the cash for clunkers deal. ;)

First thing though I guess is clean up that area then see where its leaking? Can I just spray something like orange power and wash it down with the hose and not hurt anything? Another option is take it to a MB tech.

Thanks again.

I can't believe you'd give up on this car just because of a minor leak from the head gasket.

It could leak like this for years and give you no other problems.

If it bothers you, take it to an independent and get the head gasket replaced for $1,200 and drive the damn car for the next 10 years.

I too believe you should fix the leak and keep the car. I would use a engine degreaser and clean up any traces of oil. You could continue to monitor the leakage and fluid levels. Records for my 300CE indicate that the head gasket was leaking out oil as far back as 2003. I just had the top end rebuilt this year and it was still operating fine since the leak was external and did not affect the engine compression. If your car is in otherwise good health, I would go ahead and do the head gasket at a independent specialist. With that many miles you would be wise to check and replace the valve seals and guides if they have never been done. The M103 tends to have a weak spot with those two items.

Really? I didnt know that. I thought once it started that it was not long before it would be ready for the salvage yard unless it was replaced. I have owned the car for 13 months, but not sure how long its been leaking. I know it was slowly losing coolant last winter, but I didnt have to add much. Strange, but during the summer, I never had to add any. I have not checked the coolant level in awhile (about 2 months), but the low coolant light has not came back on and the car runs cool (about 78°-82°C).

I will check the coolant next time I drive it. I should also mention I only drive this car about 2 days per week (about 80-90 miles per week).

Yeah, its not using oil now, but if I had the HG done, I would definitely want to do the valve seals, etc once in there. 2003 is a long time to have a leak... if I knew mine would be OK 5-6 years like this by only adding some coolant every once in awhile, I would not fret over it and maybe have it replaced in a couple of years. I guess I will wait and see. Thanks.

Well I can see that both of your transmission cooler hoses are leaking transmission fluid, that is a easy, do it yourself repair and parts cost less than $100.00 tops with shipping. As far as a green coolant leak on the right[passenger] side of the engine , could be a head gasket, but likely you would not see green coolant dripping off the FRONT of the oil pan. Seems to me a coolant leak at the head gasket would leak down either side of the block and migrate towards the rear of the engine due to windage.
Before you get all concerned about your headgasket, CONFIRM that it is indeed leaking, make sure that you are not seeing a waterpump or more likely a heater hose/pipe leak. Do not the M103's have a heater hose pipe coming out of the water pump and traversing to the right side of the engine under the distributor cap, right in front of the timing cover? I know my 190E 2.6 does. If I was seeing green coolant dripping off of the FRONT of my oil pan, I would look closely at that pipe and hose to make sure that it was not cracked and leaking, could be something as simple as a loose hose clamp, or that coolant pipe cracked at its mounting tab on the lower timing cover.

I should add that it was the previous owner that decided to drive it in this condition. She didn't put very many miles on the car between the time the leak appeared and the time I bought it at the end of 2008. I don't think the dealership was doing her any favours so she decided to just delay...

You should be able to do the head gasket relatively easy yourself if the valve guides are not burning any oil. You don't have to touch anything on the fuel side. Just unbolt @ the intake manifold, unbolt exhaust pipes, remove rotor, cap and ignition wires and pull her out!

Don't pay any more than $1300 for a head gasket change at an indy. The head gasket set is less than $100 and there is no way it takes 12 hours of labor. I did it in less than 6 hours and I have never removed a head before. Rebuild took me about 9 hours but I had to reassemble the head and do the water pump which required a bunch of other stuff to come off.

Outofspec:
quote; "Once off I cleaned the surface of the head and block with a pneumatic die grinder and those 3M 3” disk pads that screw lock into place."

Not to change the subject here, or start the age-old debate on such, but in my opinion, I would never clean an aluminum head surface with a power tool and an abrasive pad of any kind. Reading of the leak you mentioned after your head gasket replacement, the first thing that crossed my mind was how you might have cleaned the head. Next post you mention using this method on the head (probably not a problem on the iron block). Of course, it may or may not be the reason for the leak but curious to consider.

86560SEL: on a similar note, using the green coolant isn't considered the best practice on Mercedes' (or most cars with aluminum/alloy parts in contact with coolant). There are many who would expect that the use of the wrong coolant could be corrosive or antagonistic to the sensitive metals in the system and result in such leaks. MB coolant or Zerex G-05 are the standard recommended coolants to use.

lol. I know. I have been meaning to change it.... too little time and money. Poor excuses I know. ;)

Ehhh, I would not worry about the oil leak. As long as you keep an eye on the level, you will be fine. My 300TE leaks where the upper timing chain cover meets the lower timing chain cover. Its not too bad of a leak, but you can definitely see the oil leak there.



Your water pump could also be starting to leak a little. Would not hurt to clean up the engine bay, and identify the leak.



A friends got well over 275k on a 190E 2.6, and he leaks transmission fluid, oil, and until recently, coolant. The water pump had a slow leak when the engine was at operating temperature, but wasn't too bad of a leak to justify replacing the pump. He recently replaced the water pump, and his coolant does not disappear anymore.

Personally, I would just keep an eye on the level of the vital fluids, and keep them topped off. Paul S is right, in that you could drive the car for the next 10 years, and not have any problems.

86560SEL, as mentioned several times already take the time to thoroughly clean the engine and pinpoint the leak source. If you're still unable to detemine exactly what is leaking consider taking your car to a local, reputable indie for a professional diagnosis. Our local indie swears that the only MB automobiles that don't leak are the ones that aren't driven ... certainly that's an exaggeration. You may very well drive the car as-is for years provided you regularly check the fluid levels. Do change the coolant ASAP ... the green coolant is a no-no.

Remember to have a PPI (pre-purchase inspection) done by a MB-trained tech before buying any MB automobile in the future. That way you will find out about existing problems and the cost to repair. You will read many times on this forum "There is nothing more expensive than a cheap MB automobile".

[QUOTE=long-gone;2324327]Outofspec:
quote; "Once off I cleaned the surface of the head and block with a pneumatic die grinder and those 3M 3” disk pads that screw lock into place."

Not to change the subject here, or start the age-old debate on such, but in my opinion, I would never clean an aluminum head surface with a power tool and an abrasive pad of any kind. Reading of the leak you mentioned after your head gasket replacement, the first thing that crossed my mind was how you might have cleaned the head. Next post you mention using this method on the head (probably not a problem on the iron block). Of course, it may or may not be the reason for the leak but curious to consider.

I can understand your concern here Long gone. I used the least most aggresive 3M pad available for the head and was very aware of the pressure and speed on the air tool while removing the old gasket reminents. I feel it's important to get both mating surfaces clean as a whistle before placing any new gasket. The leak that I mentioned after the work was done did not occur on the head gasket, but the new water pump where it meets the block. I actually got the large rubber "O" ring pinched and not seated properly. The solution was to anchore the new "O" ring to the back of the new pump with a little sealer that I used on the upper timing chain cover. This held it in place for installation and made certain it was in straight. 450 miles and counting on the new head gasket. No leaks!

Thanks. Well, if it does turn out to be the HG, I will probably try to turn it over to someone that can fix it themselves and enjoy for 15 more years. :)

I am not a DIY'er and cant afford a big repair. Hopefully even if it is the HG, it will last alot longer.

Before you decide it's the head gasket, do yourself a favor and clean everything up. Also, you're likely to need to re-seal the front top timing cover. These love to leak oil.

The coolant could also be leaking from the various hoses and connections and dripping all over the place. The fan can also spread fluids around. That's why cleaning up is so important for finding a leak.

Check the O-ring going to the heater tube on the water pump. It can leak.

Did I hear you say you have GREEN antifreeze in there? Big no-no. Switch to the MB stuff or you'll regret it eventually.

Check those transmission cooler hoses, they looked a bit weepy.

Thanks. Yeah, I am going to try to clean it up, but it will probably be first of next week... full plate. Work everyday until Tuesday... church Wednesday night, washing/waxing a friends car Thursday night, Halloween deal at church Friday night, cruise-in (last one of the year) on Saturday night, so MAYBE Sunday night or Monday night at the latest. I will also get some pics of the engine from the upside. Seems like its originating from the upper area, below the valve cover gasket, but I know there is no way to tell until I get it cleaned up good.

Yeah, its got green coolant... it was in there when I bought it. Apparently people like to use green coolant in these cars. I may even post some photos later this evening of what the upperside looks like so far.

OK... well I took more photos of where I think its leaking, but for some reason my computer is being a PITB and not wanting to read the SD card... another thing bites the dust so to speak. :rolleyes:

Anyway, I noticed some coolant on the upper part of the water pump. I think its leaking at the pump, but wondering if the head gasket could also be seeping? I did take more photos after cleaning it up and will post when I get this thing working.

I will let it all dry good and drive it once and see if I can see more coolant and where its coming from.

Very well. I got the photos to download into my computer... here goes.

This was before the cleaning... the ones I posted before were not of inside the engine bay...

It appears to be that there is some sealant/glue there and it looks like it has had some work there before???? I dont know...

http://i39.photobucket.com/albums/e1...otos/006-3.jpg

http://i39.photobucket.com/albums/e1...otos/007-2.jpg

http://i39.photobucket.com/albums/e1...otos/014-1.jpg

ut oh... here is coolant! I wonder if this is the problem and if its just that hose and not the head gasket...
http://i39.photobucket.com/albums/e1...otos/015-4.jpg
that housing appears rusty...
http://i39.photobucket.com/albums/e1...otos/037-1.jpg

http://i39.photobucket.com/albums/e1...otos/016-5.jpg

after the cleaning... I guess tomorrow I can check and see where its leaking...

http://i39.photobucket.com/albums/e1...otos/029-1.jpg
http://i39.photobucket.com/albums/e1...otos/033-4.jpg

as you can see, it has Mercedes hoses and clamps... I am sure there is no way they are original however...
http://i39.photobucket.com/albums/e1...otos/035-3.jpg

http://i39.photobucket.com/albums/e1...otos/040-2.jpg

this is how low the coolant is... I have not added any in at least 8 months! I think I topped it off in February, when it was low and my low coolant light was illuminating.

http://i39.photobucket.com/albums/e1...otos/022-1.jpg

More info tomorrow

my 300se engine is in a similar leak condition , but no ill effects as yet over a long period . . A weak point of the the 103 engine.

mak
300se.90

well. it seems to me that the coolant is coming from the small hose between the pump and the engine head. the hose seems worn out and the head port is very rusty at that point (pics 4 & 5)....

also, when looking at the thermostat housing (same pictures), there are some small and faint traces of rust and coolant marks. check the thermostat gasket........

the front timing cover might be a little leaky, but it does not look severe, at least not to me

run the car and let it warm up and idle, then you should be able to see the leak, especially the coolant leak...

Thanks. Thats what I was thinking as well... that small hose. I guess I will go ahead and replace it and see what happens. It almost looks to easy to change... its a very small hose as far as length goes... is there any trick (such as having to remove anything else), or will the hose come off without having to remove anything?

I actually drove the car 87 miles today and checked it when I came home and I cant tell anything about it... its not leaking enough at this point to tell.

As you can see, there is nothing to see at this point... I took these this afternoon after it had been driven for nearly 90 miles. The leak is very slow obviously....

http://i39.photobucket.com/albums/e1...photos/002.jpg

http://i39.photobucket.com/albums/e1...otos/003-2.jpg

http://i39.photobucket.com/albums/e1...otos/006-1.jpg

http://i39.photobucket.com/albums/e1...photos/016.jpg

Its actually not an easy hose to replace....I believe you have to remove the water pump to get it off. I replaced mine when I did my WP.

Start by simply tightening the rings up and see if it helps. A little coolant loss is no biggie as long as you keep her topped up. Be careful though you don't want to tear through the hose.

I don't see the front timing cover leaking either. If it was leaking it would be covered in oil streaming all the way down. Its dirty -- yes, but not leaking dirty.

Remove the water pump to replace? Wow. For some reason it looked like it would be harder than it appeared to be to replace. :(

I think changing the water pump is a PITB on these cars isnt it?

My luck has been so bad lately. Just found out that the power steering pump on my Lexus may be bad. Well, at least this leak is only minor... at this point. I didnt seem to leak at all in the summer... cooler weather seems to cause it to leak more because when it did leak before, most of it was in the winter.

In reply to the timing cover, those last photos were after I had cleaned the engine yesterday, but even after a 90 mile drive it looks all dry... are you referring to the looks of it in the earlier photos before the washing? I am just hoping its not the timing cover or the head gasket.

I let the car set overnight and checked it again this evening.

There is coolant pooled up under that very short coolant hose that I have posted above. I will see if tightening will solve the problem.

Hope it will, but something tells me it will not... never that simple.

Not good considering that I think my Lexus is going to need a power steering pump... another $$$ repair. :(

Oh well, we will see. :o

Yep...either remove the water pump, or the head ;)
I don't see any way to get a new one on without doing either of the above. The pipe goes into the hose quite far on both ends, that is why it would be incredibly difficult/impossible to fit a new one without removing one or the other.

Thanks. Well, that is a foolish design isnt it? They should have made those shorter. Anything to have to pay someone for more labor.

I wonder how much this would cost at a typical shop?

Well, I confirmed that its definitely that hose. I drove the car 80 more miles today. It dont leak when the car is running... only seeps after its been off for awhile.

It had that small pooling in that crevice and I felt and the hose was indeed wet underneath when I felt it. We tried tightening the screws, but they wont budge. :(

I agree that is probably the head gasket leaking.

I had the same problem with my 1988 260e. I put off replacing the head gasket for two years after discovering that I could stop the leak by loosening the cap on the coolant recovery tank. It is not a recommended practice because the reduced coolant pressure will lower the boiling point, but since I only drove the car a short distance to work it didn't matter.

I finally broke down and replace the head gasket myself. parts were a couple hundred dollars including new head bolts. I also replaced the valve stem seals while the head was off.

Thanks. We have confirmed however that is that short hose that runs from the head to the thermostat area that is leaking.

Leak stopped... it was indeed the short coolant hose! I put on a new clamp and presto. Leak stopped. Thanks for all of the replies!

Wow, what an old thread of mine... 6 years ago! I ran across this when doing a search on google, lol. I thought I would update it incase anyone else has this issue while I was here. :D

I was a little dumb when it came to this car, lol. Well 6 years later we still have the car and it is going great. It has been my moms car for the last 4 years, though I still drive it often.

That leak toward the front of the engine is still there, just have to add a little oil, about a quart every 3k miles. Still no major problems with the car. We have only had to replace a ball-joint, regulator and coil since the 8 years of ownership. There is an issue with the ABS, but as an '88 model, no surprise.

You were right... 6 years later, still going and haven't replaced a thing. :) Just have to add about a quart of oil every 3000 miles. :) We did finally replace that short coolant hose last week. Also, it is a shame, but still has the green coolant in there, no problems, but I am going to change it this week. I know I put alot of things off on this car due to money issues, but I am much better off financially than I was 6 years ago, I have a much better job with great pay and have since won a brand new car that I sold and put all of the money in my savings (which I do not touch, lol), but now this my moms car, so my dad takes care of buying things for it and I normally end up doing the work, lol.

It actually wasn't too bad and it went 6 more years and was still ok, but we actually changed it earlier this week. We actually just cut the pipe a little bit and got the new hose on in about 15 minutes. :) Glad we didn't have to remove the water pump.