I think the head gasket on my 1995 E320 Wagon (184,xxx miles) may be blown. During the past 2000 miles, I noticed a loss of about 1/6 gallon coolant. Today I examined each of the spark plugs. After I pull out spark plug #6, I saw vapor coming out of the spark plug hole briefly. According to a mechanic friend, this is an indication of a blown head gasket. I did not notice oil in the coolant reservoir. The car is running normally and idling is quiet.
I am wondering if this should be a concern and immediate repair is needed. Is there a HG replacement instruction available online?

 

Traditionally, yes, that would indicate water in your engine oil. That is a HUGE concern if in fact it's true, because you can ruin an engine in short order-depending on how much water/antifreeze gets in there.

That being said, the w124's usually leak oil into the coolant system and with occasional flushing you can run them forever that way-albeit the oil can break down and burst your cooling system hoses.

You should see some evidence of water droplets on your dipstick as well, when you check it. In any event, I wouldn't gamble with water in the engine-shut it down and have it taken care of. My head is presently off and at a machine shop, but my oil leak was into my cooling system.

(Another reason you might have the reverse of the normal cylinder head gasket failure, is that you have a cracked block)

Kevin

 

Thank you Kevin. This morning, I had my wife start the car, and I was observing the exhaust. I only observed a brief gust of a very small amount of vapor from the exhaust. Then there was no more vapor in exhaust. I was thinking if head gasket fails, and coolant leaks into cylinder, then how come there is no vapor coming out of tailpipe? Any thoughts?

 

Tailpipe observation on start-up is not a good litmus test for coolant in the engine oil. Most exhaust systems 'trap' a certain amount of condensation in the pipes somewhere, waiting to spew out on start-up. You can see this in traffic most mornings, as cars are first run. You could feel the condensation as it comes out-if it's coolant, the antifreeze will have that 'slimy' feel to it and sort of a sweet smell. The absolute best way other than visual observation (water type droplets on the dipstick), is to have the oil tested. Cost you less than $50 from a lab...especially if you want a specific test for like coolant in the engine oil. You can get a block tester from NAPA to see if oil is in your coolant. I'd be MUCH more worried about coolant in my oil, however.

Get the oil tested, know for sure. Even cylinder leak down tests don't give you definitive answers on MB engines, as they have to be running for the head gasket to expand and seal properly.

Kevin

 

Thank you very much Kevin!
If the test result is negative, would we know for sure that the head gasket is OK?

I did three more checks today and want to share the results with you:
1) I smelt the exhaust both when car is started cold and when car is fully warmed up. The exhaust smells normal. I was looking for the sweet taste, but did not find it (I even put my nose very close to the tailpipe).
2) I checked the coolant reservior very carefully, and did not notice any oil in it.
3) I checked the dipstick and did not find any water droplet on it
In addition, the car is not running hot.

 

You may not see oil in the coolant...at first. That's why I recommended a block tester. Time is not of the essence if you have oil in your coolant, especially in small amounts. Your car will only run hot as the coolant/oil mixture thickens and is therefore sluggish to circulate. Mine would get like monkey pooh on long trips...even resorted to flushing the system on road trips. I love the car, but not that much.;-) Had one episode out in the desert in NM after a 140mph run with a 'tuner car'...well, let's not go there.

Yes, a good lab will give you the definitive answer on coolant in your oil. This should go without saying though...make sure the oil has been in there for awhile. In other words, don't change the oil, put a few miles on it and send off that oil sample. You want a oil sample from oil that has been in there for long miles. It worries me in your post that stated you had moisture when you removed your plugs. And the fact that your coolant is disappearing. However, coolant loss could be from other places.....after you get it warmed up, put some miles on it, park it on a level surface and then put some sheet cardboard under it.....one big piece would be best. With cardboard, you can tell where it first 'hits' (the leak), not where it runs and then you figure out the corresponding place that it falls off your engine. I suppose you could do the same thing with butcher paper et all. Not a definitive test though....you could have a leak under pressure (engine running), only.

This is a long shot, but thought I'd mention it anyway. I had Peugeot wagon once that I used to pressure wash regularly in the engine compartment. I was over looking the fact that I was forcing water into my engine through some unknown orifice. I had a cylinder head gasket that was fine, compression up etc, but had water on my dipstick/plugs. Quit pressure washing the engine, moisture went away (Peugeot gas engines are not known for head gasket problems).

So I have to ask....are you pressure washing your engine? If not, let's stick with the lab test on your oil and see what happens. If the lab test comes back negative on coolant in the engine oil, then we switch tact to the block tester for oil in the coolant.

Kevin

 

Kevin: Thank you so much for all your kind suggestions!! So if head gasket is blown, the test for oil in coolant, or the test for coolant in oil, or both tests would be positive? I ask this because I suspect that coolant is leaking into the combustion chamber, which results in vapor in spark plug hole #6).
So you are still keeping the car which gave you problems in the desert. Good car overall, isn't it?

 

Typically, there is a corner on the engine head where an oil gallery and a cooling passage are so close that if the head gasket fails, oil goes into the coolant. 95% of the time, this is the scenario. Heads warp on these cars because at some point in the car's history, the cooling system failed; one or both electric fans failed, water pump failure, radiator failure, thermostat failure etc. From what I've discerned, the temp only has to be near the red for a short amount of time and you have a warped head-the problem usually showing up at the place I mentioned above. Your problem just might be a little worse than what normally happens. Aluminum heads have the advantage of weight reduction and are easy to mill, but they do warp easily.

At least if your oil comes back negative for coolant, we can assume the gasket is blown and you're only getting coolant in the combustion chamber and most likely some oil in the coolant as well. If you have coolant in your oil, we can assume your head gasket is blown as well, and maybe something worse like a cracked block. How often that happens in MB engines, I can't tell you.

Yeah, I bought my car new, lost it in a divorce, the ex put almost 200K on it and then offered it back to me. The head is off now and down at the machine shop. The head was supposedly rebuilt by the dealer some 10K ago. In taking it off, I found intake manifold bolts finger tight that were hard to access and a few missing parts-signs of a poor, rushed reassembly job at the least. My goal is to put 500K on the car, then swap engines and shoot for a million miles. Most of its life was spent in a dry, arid climate so it's got that going for it. I want to turbo it too, after I get the motor back up and running again. Sentimental value is keeping this thing going and hell, it's sort of a challenge.

Kevin

 

Thank you again, Kevin! I had the cooling system failure issues you pointed out. The fan clutch failed, the auxiliary fans failed due to burned fuses, and the thermostat failed. I will locate the HG problem and get it fixed soon.

 

Yeah, that's classic MB head gasket failure and those are exactly the reasons for it. If you're statistically lucky and in the 95 percentile, then a new gasket and a trip to the machine shop is all you will need. Once the head is off, you can clean up the top of the block/pistons, replace the timing chain and chain tensioner....I'm even putting in new lifters all around. It's also an excellent time to evaluate your distributor & rotor, plug wires etc. The inside of my distributor cap was so green with corrosion, along with the rotor, I'm not sure how any significant electrical contact was being made!

Before I was offered the car, I was at my ex's house and she offered the car for me to drive that day. Immediately, I noticed the water temp gauge was running too hot and I didn't hear all the electric fan noise that I usually heard when I owned it. One fan was dead and the other not working because of a fuse issue-probably blown when the first fan failed. Then my sons mentioned she had the car so hot on occasion, that she would pull over and let it cool. When I agreed to buy the car, she swore to me (in front of her sister) that she would guarantee the head wasn't warped. Human Lesson 101:People who live in the World of Denial don't have to follow the same rules as the rest of us.;-)

There are even people in here that had the head gasket/head fixed and continue to have it leak many miles later. It is my erstwhile hope that if I do this right, I won't have this problem again. However, I intend to stay on TOP of any cooling issues, as any failed component could overheat the engine and cause the head to warp again.

Keep in touch with us on your car's issues, as it's wholly relevant to this site and everyone else who has/had head gasket problems. What I don't know is how many people here have w124's with high mileage and never had a head gasket issue.

Kevin

 

hi

i'm new here and i don't have much knowledge about engines. any advice from you guys would be great to help me understand what is going on with my car. so here it is, i had this 300ce for almost two years i think, i loved this car first time i saw until i had the chance to have one. it was summer of 2007 first time i had the car i notice that my temperature goes up to 100 degrees and i said this is not normal i continue to observe and my ac was not working yet at that time and i notice that my aux fan was not working so i said this is one cause why my temperature goes up. so i brought it to a mechanic and had it check cause i just got the car, water pump was replaced, fan belt, spark plugs, oil change has been done. i was still driving the car with my aux fan not working i always look at my temperature just to be sure i wont overheat. then i notice on the cluster the water light goes on and i check and put water. finally i had ac on my car and i used it & easily my temp goes way up to 100-110 degrees i pretty got scared especially when your sitting in traffic but on freeway driving im ok. then i had my aux fan replaced so i was excited to see that i won't see my temperature going up to 100 because i don't really find that normal for a w124. i did help but it still goes up most likely when im sitting in traffic. then my mechanic said he saw a small leak in my radiator i had it replaced & my mechanic also he replaced the thermostat. so i was using the car & i notice the temp stay at 80 degrees for awhile then later on starts climbing very slowly then 100 then 110 but it just stays there it doesn't go more than 110 degrees. what i notice more is that when i didn't had my radiator replace when i'm in the freeway my temp stay at 90-100 but ever since he change the radiator i was surprised coz i tested it on the freeway and my temp went up to 100 degrees and now he's telling me that it's the head gasket. he said i don't have a cracked or blown head. it just the gasket that he notice some corrosion. so i really don't know. i don't know where to look at. coz if it's just the head gasket i saw on internet it's like $90 victor reinz brand i think, but if i'll be spending thousand i don't think i have the funds for it. any advice out there would really be a great help

thank you

 

I'd be concerned over him telling you its the head gasket first of all...How does he know this? Seems odd. This shouldn't be the cause of the overheating anyway based on what you said.

I didn't get from your post if you are losing coolant or not? Is your fan clutch engaging?

 

well, aux fan is working well everytime it hits 100degrees the fan turns on automatically. i dont think so im loosing coolant. my thermostat is new radiator is new water pump working well. so i dont know what could be other issue why my temperature always go up to a 110 degrees. so what could be the possible problem here?

 

Are you sure he used the correct thermostat? I read a thread about a week ago that his Indy used the wrong one and it was completely screwing up his engine temperature.

 

thanks for the advice, i would like to check the thermostat myself. can you tell me where to locate it and tools i'll be using cause i want to check it myself.

thanks

 

I think its 8mm bolts IIRC. Its to the right of the engine (facing it)...will be either a plastic or metal cover. It has coolant hoses going into it. I suggest investing into a Haynes manual too!