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...

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1993 300E, 2.8 M104 .....

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....

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.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

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.

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.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

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.

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.