Massive Oil Leak

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hulyer1982
Posts: 2
Joined: Tue Feb 08, 2011 8:31 pm
Currently Drives:: Renault Megane 1.6

Massive Oil Leak

Postby hulyer1982 » Tue Feb 08, 2011 8:47 pm

Hi guys just wondering if anybody has experienced this problem before. I have a 55 plate 1.6 Megane and it has a huge oil leak. A couple of my mates who are mechanics looked at it and believe it may be coming from the head gasket? I then took it into Renault who believe it may be leaking from the oil seal on the thermostat housing. Once again if anybody has experienced this before or may another possible explanation for this please reply.
Lee

Reno helper
Posts: 19
Joined: Sun Feb 06, 2011 9:36 pm

Re: Massive Oil Leak

Postby Reno helper » Wed Feb 09, 2011 2:12 pm

Hi mate, It could be the thermostat housing as this is quite common as their are oilways and waterways on the end of the cylinder head, and as the thermostat housing is plastic and deforms with the heat and causes it to leak. head gaskets arn't very common.

davelowe
Driving Legend
Posts: 3138
Joined: Thu May 10, 2007 3:40 pm

Re: Massive Oil Leak

Postby davelowe » Wed Feb 09, 2011 10:39 pm

How bad is it? Remove the engine undertray (assuming you haven't already), as much ducting/kit as you can from the engine bay and mop it all up clean with a rag. Ideally, de-gunk it spotless. Then idle the engine until warm while observing. Driving around only makes things confusing since the oil will spray all over the place. Often the oil isn't coming from where you think it is. Rev it to increase the oil pressure.

Check the oil level isn't decreasing. Check the coolant for a oily film to rule out the head gasket.

The seals are prone to fail as mentioned. They are generally very easy to replace (although probably not near the thermostat).
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Reno helper
Posts: 19
Joined: Sun Feb 06, 2011 9:36 pm

Re: Massive Oil Leak

Postby Reno helper » Sat Feb 12, 2011 11:50 am

Hi again, oil in the water doesnt mean its the head gasket, as the oil runs at a higher presure than the water it will be forced from oil into water rather than the other way round, like i said in my prev post, there are oilways and waterways on the thermostat end of the head and thermostat housings are common. At least in the last 16 years i've been working on renaults of all kinds i've not come accross a k4m/k4j type engine just decide to blow its head gasket without any other factor involved, i.e a hole in the radiator or a burst hose.

hulyer1982
Posts: 2
Joined: Tue Feb 08, 2011 8:31 pm
Currently Drives:: Renault Megane 1.6

Re: Massive Oil Leak

Postby hulyer1982 » Mon Feb 14, 2011 7:44 pm

Thanks for the replies guys the leak was indeed coming from the oilway on the cylinder head. They also changed the cam pulley and belt as i was getting the common noise when starting the car although these were done under warranty as they were only changed 10 months ago. There was also signs of the water pump leaking so that was also changed. Needless to say it wasnt cheap but mother in law works there so got a very good discount. Once again thanks for your replies
hulyer1982

brettd1
Posts: 3
Joined: Mon Aug 08, 2016 5:57 pm
Currently Drives:: Megane 1.6vvt estate

Re: Massive Oil Leak

Postby brettd1 » Mon Aug 08, 2016 6:01 pm

I'm having same problem except not sure where leak is from. Can oil enter coolant through thermostat housing? Top of header tank was about an inch thick in gunk but nothing in oil filler cap or dipstick.

everson38
Posts: 11
Joined: Sun Feb 04, 2018 10:30 pm
Currently Drives:: Megane Mk 2 2006

Re: Massive Oil Leak

Postby everson38 » Sat Feb 10, 2018 10:08 pm

Reno helper wrote:Hi again, oil in the water doesnt mean its the head gasket, as the oil runs at a higher presure than the water it will be forced from oil into water rather than the other way round, like i said in my prev post, there are oilways and waterways on the thermostat end of the head and thermostat housings are common. At least in the last 16 years i've been working on renaults of all kinds i've not come accross a k4m/k4j type engine just decide to blow its head gasket without any other factor involved, i.e a hole in the radiator or a burst hose.



Hello I have just coe across your post and I'm having similar. Just to clarify was yours a blown head gasket or thermostat housing?

Any help appreciated.

everson38
Posts: 11
Joined: Sun Feb 04, 2018 10:30 pm
Currently Drives:: Megane Mk 2 2006

Re: Massive Oil Leak

Postby everson38 » Sat Feb 10, 2018 10:12 pm

hulyer1982 wrote:Thanks for the replies guys the leak was indeed coming from the oilway on the cylinder head. They also changed the cam pulley and belt as i was getting the common noise when starting the car although these were done under warranty as they were only changed 10 months ago. There was also signs of the water pump leaking so that was also changed. Needless to say it wasnt cheap but mother in law works there so got a very good discount. Once again thanks for your replies
hulyer1982




Hello I have just coe across your post and I'm having similar. Just to clarify was yours a blown head gasket or thermostat housing?

everson38
Posts: 11
Joined: Sun Feb 04, 2018 10:30 pm
Currently Drives:: Megane Mk 2 2006

Re: Massive Oil Leak

Postby everson38 » Thu Feb 15, 2018 10:56 pm

brettd1 wrote:I'm having same problem except not sure where leak is from. Can oil enter coolant through thermostat housing? Top of header tank was about an inch thick in gunk but nothing in oil filler cap or dipstick.
hulyer1982 wrote:Thanks for the replies guys the leak was indeed coming from the oilway on the cylinder head. They also changed the cam pulley and belt as i was getting the common noise when starting the car although these were done under warranty as they were only changed 10 months ago. There was also signs of the water pump leaking so that was also changed. Needless to say it wasnt cheap but mother in law works there so got a very good discount. Once again thanks for your replies
hulyer1982


Hey mate I think I'm having the same issue. I'm just wondering how did you get in with your problem and what was the fix in the end?

stuartac
Posts: 7
Joined: Tue Mar 18, 2008 8:46 pm

Re: Massive Oil Leak

Postby stuartac » Wed Feb 21, 2018 12:02 pm

Hi all

If anyone has fixed this problem by fitting a new thermostat housing gasket, is it OK to fit the 'silicone elastomer' one (Elring 36467) which is easily available, or should a different type be used? If a different type is preferable, then what should that be?

Thanks for the help. Stuart

leaderpup
Posts: 1
Joined: Sun May 26, 2019 6:44 pm
Currently Drives:: Renault Laguna Coupe, Renault Megane 1.6 CC

Re: Massive Oil Leak

Postby leaderpup » Sun May 26, 2019 6:51 pm

Hi, Just thought I'd share that my son's Megane had a pretty bad oil leak, literally dripping off the sump when the engine was running. Anyway, had a look and was fairly confident that it was coming from the thermostat housing. Got one of the silicon ones off ebay for £4.99 and a couple of hours later (I like a coffee break) and the leak was fixed.

vanmanpaul83
Posts: 14
Joined: Sun Feb 24, 2019 7:45 pm
Currently Drives:: Renault Megane 2 1.6 16v Maxim

Re: Massive Oil Leak

Postby vanmanpaul83 » Sun Sep 01, 2019 9:52 am

leaderpup wrote:Hi, Just thought I'd share that my son's Megane had a pretty bad oil leak, literally dripping off the sump when the engine was running. Anyway, had a look and was fairly confident that it was coming from the thermostat housing. Got one of the silicon ones off ebay for £4.99 and a couple of hours later (I like a coffee break) and the leak was fixed.


Bumping an old thread here but as stated the thermostat housing (plastic) warps with age and oil starts seeping from this. If you have a severe leak and the thermostat housing is warped you can visibly see this but can put a metal engineering ruler across the face of the thermostat housing and this will show how bad the warped face is. Unless the rubber sealing gasket has actually deteriorated and this is the only issue then a new thermostat housing is the only way to fix this problem. The benefits of a new thermostat apart from fixing oil leak and oil and coolant cross contamination are you'll be replacing thermostat and coolant temperature sensor. The thermostat cannot be replaced alone as its sealed in the housing and the new housing comes with a new coolant temp sensor. If the oil has been forced into and mixed with coolant then a full flush of the coolant system is advised. As stated this gives false indication of blown head gasket.


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