Headgasket or cleaning misadventure...?
Discussion
One of my mates called me today all panicked that his HG had gone on his Merc. He took off the oil cap and found a big wodge of tell-tale creamy muck-muck stuck to it. I got him to remove the oil filter to check in there, which proved 100% fine with the oil still golden (recently changed) and no creamy stuff in sight.
He's not seen any increase in engine temps, or any unusual noises and the coolant is clean. So I was a bit baffled.
I delved a bit deeper and found that he'd recently changed his valve cover gaskets and had used brake cleaner to clean up the remains of the previous gaskets. If any of this hadn't dried before he started the car, could small amounts of the brake cleaner have caused it?
I'm tempted to get him to do an oil/filter change and see how it goes, but some thoughts from the experts would be appreciated.
He's not seen any increase in engine temps, or any unusual noises and the coolant is clean. So I was a bit baffled.
I delved a bit deeper and found that he'd recently changed his valve cover gaskets and had used brake cleaner to clean up the remains of the previous gaskets. If any of this hadn't dried before he started the car, could small amounts of the brake cleaner have caused it?
I'm tempted to get him to do an oil/filter change and see how it goes, but some thoughts from the experts would be appreciated.
Blue Oval84 said:
It's just the time of year, my guess is that he does shorter runs of less than 10 miles?
My Z4 has filled with gunk previously when used during the winter on short runs. It's the condensation in the oil which doesn't get hot enough to burn it off.
Ahh interesting, I've not heard of that before (but then I'm a n00b myself).My Z4 has filled with gunk previously when used during the winter on short runs. It's the condensation in the oil which doesn't get hot enough to burn it off.
Yes he does only do really short trips in it most of the time. Sounds like you could have hit the nail.
sparks_E39 said:
It's condensation. I get gunk under my filler cap and sometimes on the dipstick this time of year and have done for the past 3 years as work is a 6 mile 10 minute trip- I take it for a 30-50 mile blast most weekends to give it a bit of a run.
I notice you drive a BMW...I'm not sure of this applies to your BMW or not as it has the M52TU engine as opposed to the M54 fitted to the facelift E39.
The M54 engine has a Crank Case Ventillation valve (CCV). This is connected to the top of the engine via a pipe (Top right hand front corner as you look under the bonnet). It feeds vapours that come of the top of the engine into the inlet manifold while allowing any liquid carryover to return to the sump (it connects in next to the dipstick)
The CCV is a known weak spot and it frequently sticks. Thios stiops water vapour escaping from the top of the engine resulting in a build up of cream sludge. It can also result in the same material building up on the bottom of the dipstick since that is where the valve connects into the sump.
You can check it's working correctly by removing the oil filler cap when the engine is running. If the valve is working this will allow unmetered air into the inlet manifold and result in the engine idle changing noticably. If you place a plastic bag over the top of the open filler nozzle you should notoce the bag being sucked in as the CCV results in a slight vacuum in the top of the engine. As a final check remove the pipe to the CCV from the top corner of the engine and if it's full of white gunk it's a sure sign you have a problem.
The good news is that a new valve is only about £30. The bad news is it's a pig to get at. I've done two, one on an E39 530 and one on an E46 330.
Devil2575 said:
I notice you drive a BMW...
I'm not sure of this applies to your BMW or not as it has the M52TU engine as opposed to the M54 fitted to the facelift E39.
The M54 engine has a Crank Case Ventillation valve (CCV). This is connected to the top of the engine via a pipe (Top right hand front corner as you look under the bonnet). It feeds vapours that come of the top of the engine into the inlet manifold while allowing any liquid carryover to return to the sump (it connects in next to the dipstick)
The CCV is a known weak spot and it frequently sticks. Thios stiops water vapour escaping from the top of the engine resulting in a build up of cream sludge. It can also result in the same material building up on the bottom of the dipstick since that is where the valve connects into the sump.
You can check it's working correctly by removing the oil filler cap when the engine is running. If the valve is working this will allow unmetered air into the inlet manifold and result in the engine idle changing noticably. If you place a plastic bag over the top of the open filler nozzle you should notoce the bag being sucked in as the CCV results in a slight vacuum in the top of the engine. As a final check remove the pipe to the CCV from the top corner of the engine and if it's full of white gunk it's a sure sign you have a problem.
The good news is that a new valve is only about £30. The bad news is it's a pig to get at. I've done two, one on an E39 530 and one on an E46 330.
Thanks for that, I have heard of the issue. I get it every year and don't have an idle problem. My indie had a good look at it last service and said it's nothing to worry about, I may change it though this year.I'm not sure of this applies to your BMW or not as it has the M52TU engine as opposed to the M54 fitted to the facelift E39.
The M54 engine has a Crank Case Ventillation valve (CCV). This is connected to the top of the engine via a pipe (Top right hand front corner as you look under the bonnet). It feeds vapours that come of the top of the engine into the inlet manifold while allowing any liquid carryover to return to the sump (it connects in next to the dipstick)
The CCV is a known weak spot and it frequently sticks. Thios stiops water vapour escaping from the top of the engine resulting in a build up of cream sludge. It can also result in the same material building up on the bottom of the dipstick since that is where the valve connects into the sump.
You can check it's working correctly by removing the oil filler cap when the engine is running. If the valve is working this will allow unmetered air into the inlet manifold and result in the engine idle changing noticably. If you place a plastic bag over the top of the open filler nozzle you should notoce the bag being sucked in as the CCV results in a slight vacuum in the top of the engine. As a final check remove the pipe to the CCV from the top corner of the engine and if it's full of white gunk it's a sure sign you have a problem.
The good news is that a new valve is only about £30. The bad news is it's a pig to get at. I've done two, one on an E39 530 and one on an E46 330.
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