Shop says I need a new engine...300E
 

I was driving to work this morning going up an incline and strangely enough, the same incline I had this happen before on, the engine overheats (it's not even a steep incline)! I had just replaced the head gasket 1200 miles ago with no loss of coolant or oil since. When I pulled over, the only place I was losing coolant from was the expansion tank overflow hose. Any idea what may have happened? I had the car towed into a friends shop and he just called and said there are two cylinders with no compression and that I need a new (used) engine. I am about to part ways if so...:(

How hot did it get? Was it in the red, and if so for how long of a time. It could be the head gasket failed on you again. From that I would hesitate to think the whole engine is toast!

I don't see under the circumstances you describe, how you could lose full compression on two cylinders out of nowhere. Is there any coolant/oil mixing? I'm suspicious. How good is this friend? ;)

My guess is that I need the head redone and not a new engine based on what I've read here in the past. There were no external leaks prior to this happening and everything was fine. I was driving 130 miles round trip and checking fluids daily. It was starting and running great!

When I noticed it was hot, I don't know how long the gauge had been in the red but it was pegged there. I was able to coast downhill while manuevering though traffic to the shoulder and it wasn't acting or sounding bad but I guess that doesn't mean anything.

See if you can do a leakdown test, those numbers would be more valuable than the compression right now. If you don't know how long it was in the red, that's not a good sign for the engine. :(

yeah, you're right John. I'll have to see what he comes up with engine wise. My searches have been 1000K + for a used one. Any ideas? I always scan my dashboard but didn't notice how long it had been running since no light popped on and everything felt normal. I just happened to notice the needle pegged to the top when I checked the clock and car was behaving fine. I didn't even have smoke until I pulled over and stopped and then a little started coming out on the expansion tank side and not a lot more after I opened the hood.

M103s are easy to find, you can easily find them for 500 bucks or less. They're used and haven't been rebuilt but lots of guys are parting out these cars

That would be great if I can find one for that price!

My guess would be that it's the result of hand sanding the old head gasket off with 200 grit sand paper and/or the mineral concretions that you described were clogging your water jackets. If you could see openings that were visibly obstructed then it's likely there were obstructions in other places out of view.
Did you do a good coolant flush afterward?

The head could probably be properly resurfaced at machine shop, but if you used the sand paper on the block too that might be a big problem. Otherwise, while these engines aren't immune to ringwear, they have a notoriously strong bottom end. Unless there was some kind of piston damage to those mentioned cylinders, a refurbished head, a new (carefully done, not hurried) head gasket and a thorough coolant flushing might bring it back to use again.
I think I remember you mentioning that you could see evidence of coolant leaking into a cylinder or two when you had the head off, was it the same cylinder/s that the shop say lost compression?

All that being said, if you can find a used M103 for $500 or less (and I agree that's very possible) it might be cheaper and easier to go that route. Be aware though that any used M103 you get might be just a few thousand miles from needing a new head gasket as well.

sptt, it's odd the low coolant level warning light didn't illuminate during this overheating/loss of coolant incident. If your friend isn't a MB-trained tech I would have an indie who is evaluate the condition of your engine, and propose the most sensible and cost effective repair method. If the indie has a borescope he can remove the spark plugs and inspect the cylinder walls to see if any cylinder walls or pistons are toast. Pulling the head will reveal head gasket failure or valve problems.

As mentioned any blockage of coolant passages is undesirable so that's a major consideration befoe deciding to repair your existing engine. On the other hand buying a used engine has a downside since you probably won't know its service history, and it may require major repairs in short order.

which car? what engine? 2.6 or 3.0?
I have a 90 2.6 running when wrecked, for 300 if you want it. I'll crate it up and have it ready for you.

Overheating an engine is always undesireable, but it doesn't necessarily finish it. Beings the radiator hose didn't burst, and immediately out of water is better. Kind of only you know how hot it was like if it wasn't pinging or knocking. If the rings didn't get hot enough to loose their flex on those cylinders, it could possibly eliminate the bottom end. Once you take the head off, and have it magna fluxed it will tell you if it is good or not, and if you are going to have to replace any other components in the head. Beings you had top end trouble before & all it could be like rolling the dice as to fixing the existing engine or replacing it with a good used one. Price wise and all it might just be a toss-up.

Did you have the head shaved and block checked for flatness before replacing the HG? If not they may have been warped and all you would need is to resurface them and replace the HG.

VSTECH...it is a 1991 3.0 :( I don't suppose it would work would it?

Also, yes...there was a ton of corrosion when we took the head off and who knows what else was left in there that we didn't get out. We flushed the you know what out of it, but before that, used compressed air to blow out all of the crud in the head and bottom that we could. I think that this car has had several owners so who knows what else was in there? Also, it could have very well been the hand sanding and a warped head (we measured with some tools my friend had from his shop but who knows for sure). I just didn't have the option at the time to get the head skimmed or the money, and I still don't. I was hoping to get at least a little longer out of that job so now I will keep hunting for a better price as I just don't want another new car payment just yet! :D Thanks for all the input. I have a rental car right now and it doesn't even come close to the ride or quietness of this car.

Wow. If the block surface was corroded? That is bad news. You should never even take sandpaper to the block, the sealing surface is that sensitive. And if the head wasn't skimmed by a machine shop....surprising it's made it 1200 miles! So yea, new engine time most likely.

Ferdman...yes! That was the strangest thing. When I opened the hood I wasn't losing any coolant through any hoses anywhere and I had no knocking or pinging but the engine still overheated. I thought that was perplexing as well and when I opened the hood, the coolant was still in the expansion tank but squirting out of the overflow hose like crazy so I loosened the cap and of course it started bubbling out, but not the normal symptons one would expect. The waterpump is new. I filled it back up with coolant I had in the trunk and cranked it and you could hear the coolant circulating through the dashboard but no start and it cranked very easy with little to no compression...???

John M...So would putting a new head on not be a good idea either? I found a place out here that sells remanufactured heads for $950.00. Would the gasket protect the bottom of the engine from anything that had been done previously or that I may have done?

sptt, before deciding whether to buy a reconditioned head or a used engine determine the condition of your existing engine. Pull the head yourself and examine the head gasket, cylinder walls, head and valves. If everything looks OK, except for maybe a blown head gasket at the 2 cylinders that lacked compression, take the head to a reputable indie or a machine shop so it can be checked for flatness, and the valves inspected. Experienced techs will be able to advise you whether to spend the money to recondition the existing head or move on. You may want to have an indie inspect the cylinder walls/block so you have a professional opinion on that also. Be sure to confirm that there is no coolant in the oil.

Guys...one other question. If I do swap out the engine, can the transmission friction discs that cause the delayed drive and reverse engagement, be replaced without removing the tranny at that time? Was wondering if I could kill two birds at the same time.

Ferdman...I wish I had the time and resources to do what you suggested but, unfortunately, I'm at time's mercy. Considering all of the issues I've had with this engine since I bought it, am considering just doing the swap. I found a tested, used engine online with 78K. Contemplating it at this time...

That would be super if you can come up with an engine with only 78K on it. You could get some serious service out of that! Where is the transmission at for that motor? Can you get it, as well? That would be an ideal swap if you could all at the same time.

sptt, I agree with Rebe buy the 78k mile engine with the transmission attached and do the swap. If that transmission is not available then rebuild your transmission while it's out of the car.

...even better. I found one in Wisconsin today that has 66K on it has been "tested", and comes with a 6 month warranty (can buy a 36 month parts and labor for $300.00...is that worth it?). Free shipping as well. So far, best deal I could find. The shop said if they can rebuild the trans for me while engine is out, they will. That would be worth it since EVERYTHING else is now new in there.

I think I would have to move into the 'replace the engine' camp on this one. As a matter of fact, given some of the input regarding the motor's history, condition and your financial disposition, I wouldn't even waste any more money having it checked any further.

If you do go the new motor route, don't forget to pull the head from the old one, if you get some cash, have it redone at a good machine shop and you'll have it on hand if you need it later. If you move on to another vehicle you could probably easily sell it to someone who needs it here for what you have in it. Also keep the intake with the fuel system and gadgets attached (will the new motor come with it's intake & fuel distributor?). Some other things to save might be the new water pump you just put on, the belt tensioner, wires and dist. cap/rotor (if new), coil, and the fan bearing bracket.

Take lots of photos so you know how to hook everything back up on the new motor.
Good luck

sptt, strongly recommend that you have the tech who will be doing the engine swap talk directly to the seller of the 66k mile engine to verify 1) what peripherals, if any, come with the used engine, 2) that the used engine is a duplicate of your existing engine so that wiring harnesses, linkages, etc. match exactly, and 3) what specifically is done to qualify the used engine as "tested".

As for the transmission rebuild get a firm quote beforehand so you know the cost up front, and avoid any surprises. Also, confirm the tech at your shop has experience rebuilding MB transmissions and offers a warranty on his work.

Ferdman...Got it! I have been wondering what "tested" meant and am skeptical with parting with my money and ordering online. There is a place here locally that rebuilds mercedes engines. The one I found with 66K is $1245.00 delivered. Almost everything under my hood is new except the engine and tranny so all really need is a compatible engine, no? The place I called and got the price from was...http://www.engineandtransmissionworld.com/warranty.php... I'm still contemplating what to do. Fix it or buy a new one. There are a lot of "junkyard" engines out there for around $500.00 but they look pretty bad and seem like more of a gamble. Appreciate the advice. I wonder if it would be better just to rebuild the head and skim it good? Which is more of a gamble? Sighhhh...

sptt, the exterior appearance of a used engine doesn't matter, but the internal condition is critical. That relates to regular oil changes, use of proper coolant, routine spark plug & ignition component replacement, use of premium gasoline, and a guarantee the engine was never overheated so as to warp the head. While a vendor may offer to replace a non-performing used engine it's likely that same vendor will not pay labor costs. Best to deal with an established, reputable vendor even if their price is slightly higher.

I've got some emails and calls out to some local rebuild shops for pricing. Will keep you guys posted and thanks again for the input. Helps me to think this through!

Update...I found an engine here in So Cal that I'm having installed. The guy I ended up buying it from told me that if there is an engine out there with less than 100K on it, someone is either lying or they should be charging upwards of $1400.00-$1600.00. One guy through the internet told me he had one with 63K for $950.00...really? After 21 years? How could someone realistically prove that on an engine of that age? I hope being a healthy skeptic pays off for me.

I recently bought my daughter an 89 190E 2.6 with 75k original miles. One owner, dealership maintained to 67K. I found it locally on Craigs List. I looked at a lot of cars, most in the 140K range, before finding on this one. they were asking $2800 and I got it for $2300. They're not falling out of trees, but they're out there.

I found one for $800 through my local salvage yard. Mechanic said it was in pretty good condition. It had 110k on it. It runs good but I think valve stem seals will be in order soon. Here's a pic of what happened to my old engine. Pretty much every lobe of the cam looked like that.
It went into the red more than once but I didn't have the funds to fix it at the time.

You replaced the whole engine or just the cam and rockers? I hope the later!

Pre 89 models have the older style camshafts that score as shown in the photos -- even moreso if you don't run diesel-grade oil with the zinc additives that our cams REQUIRE.
That is why it is imperative that you keep oil changes 3-4k and use of diesel-grade oil such as Rotella-T 15-40.

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Make sure your tranny gets the front pump resealed and b3 bands replaced, once that is done, the 722.3's are bulletproof. They rarely fail. Since it shifts fine, leave it alone other than the pump + B3!

Awesome. Thanks ps2cho. And no, it is the whole engine :(

Update...Transmission has been rebuilt. I found a guy in Orange County called the "Transmeister" and he only does MB trannies. He told me all I should need based on my symptoms are the b3 friction discs replaced and front pump resealed (as well as a new gasket and filter). Well, that would have been it but he also found a cracked b1 piston case that cost 107.00 and was causing the clickety sound in reverse. So, $500.00 later, it should be rock solid now. Everyone else wanted to do a full rebuild or just put in a remanufactured tranny. Thanks ps2cho!
I am just waiting for the replacement engine to get put in now, connected, and fired up. The mechanic had the engine out and the tranny in 6 hours without a lift and by himself. So, I'm guessing it'll be ready tomorrow...:confused: