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My "top off coolant" light has been coming on this week and this weekend was the first chance I got check it out. The reservoir is pretty empty, nothing even close to the fill line. I shined a flashlight on the side of the tank to see if I can see how low it is and don't really see anything.
SOOOOO I dreaded looking at the oil dipstick, pulled it out and it was wet WAY past the max line and the color wasn't dark brown.....SIGH....blown head gasket then ??
I'm going to call my mechanic tomorrow and bring it in but if it is a blown head gasket what am I looking at for repairs?
You'll have to do both banks, so plenty. Which engine, whats the service history and how far has it travelled? Head gaskets, at least on the gas engine, are pretty rare.
You'll have to do both banks, so plenty. Which engine, what's the service history and how far has it travelled? Head gaskets, at least on the gas engine, are pretty rare.
2011 ML350 4matic, I'm the original owner so service is on point. I drove it for 2 days after seeing the "top off" icon first come on.
But the car ran fine and I didn't get any other CEL stuff come on.
Get that oil milkshake out of there...
Pull the plugs and you MIGHT see which cylinder is getting hit with coolant. Any sign of white smoke (steam) from the tailpipe?
I'd also be obsessively researching to find if there are any other ways on this engine that oil and water can be mixed. Seems like someone in another thread thought their water pump gasket had failed and led to water being pushed into the oil.
Last edited by rapidoxidation; 02-19-2024 at 02:24 PM.
Get that oil milkshake out of there...
Pull the plugs and you MIGHT see which cylinder is getting hit with coolant. Any sign of white smoke (steam) from the tailpipe?
I'd also be obsessively researching to find if there are any other ways on this engine that oil and water can be mixed. Seems like someone in another thread thought their water pump gasket had failed and led to water being pushed into the oil.
I'll be dropping it off at my mechanic's tomorrow morning.
No sign of white smoke from the exhaust.
Some else suggested it might be at the oil cooler or oil filter housing?
The oil cooler seals are a common failure. It has two rubber gaskets that should be replaced. One where the cooler unit attaches to the housing and also where the housing attaches to the block. They compress over time and with heat they let the water and oil mix. It's a simple DIY fix if they've perished. Based on the low frequency of head gaskets on these engines, its fair to suggest its more likely to be the oil cooler seals than the head gasket. I'd take the advice from others and get the oil changed pronto. You didn't say how far its travelled.
Last edited by BlackML550; 02-20-2024 at 03:43 AM.
Good for you. Its as these cars age that maintenance you've already been doing starts to matter. The cost of some works can be uneconomic, to the point that you end up writing them off. Good to see a simple outcome.
They used G48 50/50 (Blue) coolant , looks like that should be fine for Mercedes Benz?
Yes, that is the correct coolant for your car. Best to check the MB Spec No. each time to make sure it suits the car but Im 99% sure the G48 is correct.
Well last week the SUV dumped a ton of coolant on my driveway.
I had to have it towed back to the shop that replaced the thermostat.
They told me the radiator upper hose clamp came loose and they just replaced it for $56 without charging me labor or additional coolant.
Now I don't like to accuse shops but it seemed too coincidental that it came loose OR they didn't connect it properly when they replaced the thermostat? I say this because not charging labor or additional coolant shows me they didn't make any money on this job.
I see a two scenarios, I'm sure there are others:
1) they didn't put the hose back on properly and a loose clamp means the hose blew off once the system had pressure. Best case scenario.
2) the radiator outlet tube no longer has a raised flange on it that the hose grips onto, with the clamp to stop it from sliding off - you need a new radiator. The hose will come off again.
Good luck and keep us updated!
Last edited by rapidoxidation; 03-04-2024 at 09:28 AM.
I see a two scenarios, I'm sure there are others:
1) they didn't put the hose back on properly and a loose clamp means the hose blew off once the system had pressure. Best case scenario.
2) the radiator outlet tube no longer has a raised flange on it that the hose grips onto, with the clamp to stop it from sliding off - you need a new radiator. The hose will come off again.
Good luck and keep us updated!
Well they told me the clamp (which they said is not a normal one where you can screw it tighter) securing the hose looked like it was worn and just ready to go.
I went about a week after they replaced the thermostat before this leak happened.
I'm of the impression that the Mercedes clamps are a once and done item, and aren't to be reused. Your anecdotal evidence proves it. Never had an issue with a worm drive screw type clamp, just don't overtighten it to where it starts to cut the rubber or crush the plastic radiator outlet tube.
I'm of the impression that the Mercedes clamps are a once and done item, and aren't to be reused. Your anecdotal evidence proves it. Never had an issue with a worm drive screw type clamp, just don't overtighten it to where it starts to cut the rubber or crush the plastic radiator outlet tube.
Yeah you're correct, so that means the shop should've known this and bought a new hose while replacing the thermostat.
I think in the future I'll go to my former mechanic that just specialized in Mercedes Benz. He was a bit more expensive then this current shop but maybe that's the price to pay to have it done right once.
They probably don't know how to use these clips properly. The proper procedure is to put the clip on the housing and then insert the hose. Not the other way around. Unless the clip and hose were faulty, that's probably the source of the problem.
They probably don't know how to use these clips properly. The proper procedure is to put the clip on the housing and then insert the hose. Not the other way around. Unless the clip and hose were faulty, that's probably the source of the problem.
Yes that's where going to a shop that just specializes in Mercedes Benz (where these subtleties will be known) is where I will always take it. That extra cost from those shops is the peace of mind that it'll be done properly, I hope.
Yes that's where going to a shop that just specializes in Mercedes Benz (where these subtleties will be known) is where I will always take it. That extra cost from those shops is the peace of mind that it'll be done properly, I hope.
oh crap, here we go again...the catch tray has a small puddle, under the thermostat looks clean but on the radiator under the hose that connects to the thermostat looks a bit wet. I'll have to assess it when I get home.
I wish I could close this topic but it seems like a zombie thread!!!
Ok definitely have another leak...
Looks like somewhere below the radiator on the right side ( if you are standing in front of the SUV). Here are some pics.
Could these be more hoses that have failed?
Also I will take it to a shop that just specializes in Mercedes Benz and I will tell them what the other shop has already done so they have some context. Man how hard can it be to fix a coolant?
There's a few hoses at that point. Lower radiator hose that comes from the right side, stretching under the radiator up to the secondary electric pump as well as the Expansion reservoir. Leaks from that point could also include the drain plug as well as the expansion tanks on the side of the radiator that are known to crack (they're plastic). Good opportunity to replace them all, flush the system and be happy.
02-18-2024, 02:53 PM
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