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Discussion Starter #1
I'm looking for peoples views on the ongoing success rate of changing the gasket alone or whether other problems were found & resolved at the same time - perhaps head warping? If other problems were found, what problems were found?

I too have finally fallen victim what I believe is the head gasket failure issue (from reading the many posts on the subject on this forum) which seems to plague so many so wondering what next steps to take & whether simply changing the head gasket is kicking the can down the road? I'd like to keep the car but I don't want to spend a fortune only for it to fail again next year.

From what I've read the failure of the gasket is a consequence of something else & unless that something else is resolved then the gasket will fail again.

I my case, the car has never overheated - well at least very high temperature gauge levels.
 

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Super fantastic Mod Technical Supremo Nice Guy
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Why are you saying head gasket has gone..?
 

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Discussion Starter #3
Have had a slight over-pressuring problem for a while which has got worse and various symptoms (below). All of which I've seen on various threads on here. I guess exhaust gasses in coolant and coolant leak at the front of engine are my main indicators. Past history;

- Started off (I believe) as coolant reservoir cracking which I replaced (little suspicious at the time).

In the last 4 months or so;
- Then I had a radiator crack - fixed with external sealant.
- Then I had a rupture in the pipe to the heater matrix behind the engine - a pig to get at.
- Tested for exhaust gasses using bubbler + indicator fluid. Rapid bubbling directly related to engine speed. Dye changed colour.
- Developed a leak at front of engine behind the power steering pump so couldn't actually see where fluid came from.

Our Motor Transport dept suggested K-Seal - so added. Cured water leak within 30mins or so but still bubbled as before. Tested 2 weeks later & seemed to be no bubbling so thought "great!"

Over-pressure then came back. Tried bubbler & on applying throttle it seemed to suck air in (little) & on taking foot off throttle it seemed to expel air (little) - strange? Found gas accumulated in the water system. Coolant system still under pressure 8 hours or so after driving whilst coolant water stone cold. Remove cap & coolant tank fills up & much gurgling. Constantly having to bleed radiator.

Now I have a ruptured coolant pipe in the engine "V" so suspecting EGR coolant pipe blown (I guess) through overpressure. Given this is probably going to need a lot of work, much of which I guess would be required for head gasket - considering my options.

As with many on here - love the car and worth much more to us than the market value so I want to keep but....

Have owned the car from new, all oil changes within service schedule using fully synthetic oil. No (or sometimes up to 1l of oil) required between services.
Averages 34mpg and engine still runs really sweetly & still with loads of power (prior to recent event).
 

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Super fantastic Mod Technical Supremo Nice Guy
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have you checked thermostat ?
never done a head on one so cannot comment on what happens, as no real way of knowing until the head(s) are off.
But building up pressure, would be taking thermostat out, as this will deffo need replacing,... ,,,,,, and a High chance the same for the water pump, as its possible if the engine has got that hot that the impeller has moved, not much, but with all water pumps, the impeller will force back , because of the pressure, as the heat expands the impeller, but not the shaft.
Thermostat would be out, especially if you are considering driving it, until you decide.
Some thermostats are part of the housing, and if thats the case, cut the thermostat straps, and remove the internals...

BUT get that thermostat out..
Have known many engines the head raises because of heat, but still survived with a new stat..
Once out, if NO pressure build up, and you want to double check, before replacing the stat. or condemning the head


Over a period of a couple of weeks, slowly introduce anti freeze into the water..

Sorry cannot really help , would be using the Search Tab, see if anyone has posted , and possibly found faults once the job has been undertaken
 

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Super Moderator Technical Supremo Platinum Member
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You are describing a lot of the symptoms I had with my Kia before I bit the bullet and did the head.
In my case, slight coolant loss, nothing concrete on gas tests on coolant, no power loss, water in oil or vice versa.
No issues to worry on when pottering around town.
Even short motorway journeys at speed not an issue.
But go more then 50 miles on the motorway and she would boil up.
Or rather empty all the coolant out.
No overt leaks I could find, new stat and expansion caps, K seal, nothing.
It was only when I found the system pressurising when cold that I decided it had to be the head.
So bit the bullet.
No sign of failure of old gasket, head seemed flat but was skimmed (long story)
It was only after it was all rebuilt and I could take it for a few good runs with no issues that I was convinced it was the head gasket.

Get an engine machinist/rebuilder to check if head needs skimming.
Mine seemed flat against a straight edge but machinist reckoned it needed about 30 thou to remove a slight bow in it.
 

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Premium Member
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Discussion Starter #6
Thermostat is actually stuck open (since use of K-Seal). I have a stat but before putting in I thought I'd see how things went as it's not easy to get to.

I have read (on this forum) of someone changing just the front gasket (which is the same head as I saw the water leak from). They said it fixed it but wondered for how long?

Not experienced any excessing temperature on gauges. Sure the fan used to kick in occasionally on a hot day.

Had considered leak may be from water pump (which is an engine out job). Front head can be removed whilst in situ (I believe from a post I read on here). Would overpressure cause pump failure? Any way I can check without removing?

Posts on here seem to change the head gasket but doesn't seem to be any feedback on how long lasting it was. Was it a long term solution or did it subsequently fail & they bought a different make? Seems to be a number of unanswered "did it fix your problem" so (being a cynic) I'm kinda thinking the latter. Hence, looking for anyone who has changed the head gasket & found to to be a long term fix. I shall try responding to their posts in the hope ...
 

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if you used the liquid that's changes colour from yellow to blue pretty sure this changes only if exhaust gases present, so any/all fixes will only be temporary
 

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Super Moderator Technical Supremo Platinum Member
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Replacing the head gasket, as long as done correctly is as good as new.
HGs do not fail anywhere near as often as they used to, usual cause on modern cars is severe overheating (boiling up) or wrong diagnosis.

Your issue is that you do not know which head it is so though a PITA, really should be planning on both.
It you suspect only front head, fair enough but.....

Wrong diagnosis.....
Things like water in oil or vice versa.... when it is thermostat gasket fail or on some cars where water and oil pass through inlet manifold.

I worked on checking and double checking everything until I was sure it could only be the head gasket.... then bit the bullet.
 

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Discussion Starter #9
Never had a head gasket go on me before so this is new to me. Had a "porous" head issue on my Calibra turbo but that was a known issue so the chap that fixed it knew exactly where the failure was & had done many before.

With the Espace - there is no oil in the water. Engine never shown as overheated on the gauge - but I guess the gauge could have been wrong.

Thermostat is on the front of the engine and no oil in water so can't see how that could be it.

I read on here about faulty EGR coolers causing similar symptoms so I have that as a "possible" and can be checked en-route.

I'm suspecting the front purely because, prior to adding K-seal, water was coming out the front of the engine somewhere. So little space it wasn't possible to see. I have PMed others who fixed with HG replacement as they seem to have since ceased being "active" on this group.

Found the water leak was due to the EGR water pipe becoming disconnected somehow. I can just see then end of the pipe buried under the injection pipes. Nice!

The Indi who changed the cam belt for me and used to be an RTE, has since given up. Shame as he used to know these engines well :-(

JJ
 

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Super Moderator Technical Supremo Platinum Member
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Your issue is the same I had with my Kia.
Suspected HG issues.... in my case I had a catastrophic fail of one of the heating pipes to the rear heater, pee poor design, it failed from inside out where a bracket had been welded and removed the plating, common issue with Sedonas.
So having boiled up, I knew that head may have warped.
But still not willing to bite the bullet until 100%.

With old type fibre gaskets, fail almost guaranteed water in oil etc. Fails were common but relatively easy to do.... a mornings work on something like a Ford push rod engine.

With modern metal gaskets, fail can show classic symptoms but may only be that gas is getting into water and pressurising the system.
Order is cylinder, water jacket, oil ways.
If only a gas leak, will only get gas into water.

With diesels, at least bigger ones, it seems that the effect is not all the time either.
It takes time for a big diseasal to get to full working pressure/heat.
One report I found was a guy with similar who fitted a pressure guage into his coolant system so he could see what was happening.
Short journeys, even longer ones in traffic, pressure stayed normal...varies from engine to engine but typically between 20 - 40 PSI max (should say on your cap)(absolute pressure BTW, includes the normal 14.7psi atmospheric pressure)
When he went on a long run, he could see pressure steadily rising until the pressure cap relieved, then it emptied the system..... pressure drop when cap opens can flash boil the coolant.


Cannot give you an easy answer except to say if it is the head gasket, fixing it properly will solve it.
If it isn't, then it will not solve your problem.

If you have leaks such as the suspect pipe, K seal will not resolve for long (or at all if a split pipe) these must be fixed.
A leak will prevent system pressure from building and engine will boil up earlier. Pressure raises the boiling point.


If you have positive gas tests they are a good indication of HG fail.
As is system pressurising when engine cold/warm... how hard hoses are is a good clue.
 

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Discussion Starter #11
Well, the EGR coolant pipe was recently blown off and dumped coolant. Worried that the pump may have gone I decided to put the pipe back & see how things go. Alas, the EGR sits in the middle of the "V" so had to take injection pipes out & common rail to access the coolant pipe so took EGR out to clean whilst I replaced the pipe. For those interested - I didn't need to take the engine mount out, I popped a jack under the engine & simply loosened it. Gave me sufficient room to easily slide the cross member out that blocks things from coming out.

Looks to me like the block, as well as the head, is Aluminium or some form of alloy. From what I've read, Renault don't permit the head to be skimmed. The gasket looks to be a metal film of about 1mm. (looking at one of the ears poking out into the "V") so I guess I could skim & put a thicker gasket in but that wouldn't solve the potentially warped Aluminium block.

Seems that Renault knew about the issue & there was an update to the injection system computer for those who complained about overheating (as well as a check to see if the engine was shot.) From what I've read in the Tech notes I get the impression Renault take the view that if the HG has failed then the engine is written off.

More info here;
https://www.renaultforums.co.uk/44-heating-cooling/72641-espace-3-0-technical-note-4678a.html

Hence, really curious to see if anyone has had any long term success with just changing HG. All those I've PM'ed haven't replied & not been active since shortly after they reported the problem.

Just ordered more K-Seal & will run at lower coolant pressure (to off-gas) and accept the coolant won't get to temp. Not much else I can do within the economics of the car.

Must say - having spent £30K purchasing from new, I won't be buying another Renault. Found buying from new & looking after them (Ford/Vauxhall) previously worked well for me. Interestingly, the main dealer here had a small Skoda showroom as well as the much larger Renault. Positions are now reversed. How times have changed.

JJ
 

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Super Moderator Technical Supremo Platinum Member
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Lower coolant pressure will not lower temperature.
It will lower the boiling point and could cause issues due to that.
If you want to lower temp, you will need to put a lower rated thermostat in or remove it entirely.
Though if HG has gone, not certain this will help much.
It will reduce coolant pressure but with diesels and HG failure, issue if often compression/combustion pressure getting into coolant.

Alum block is unlikely to warp...never heard of it.
Alum heads do.
Whether they can be skimmed succesfully, despite what Renault say, is a question that can be put to a specialist engine refurbisher/rebuilder. And depends on how much needs skimming.

And yes, gasket is likely a metal shim.
If head can be skimmed, difference in compression is unlikely to be an issue.
 

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Discussion Starter #13
Thanks, but I'm not seeing over-temperature problems - never have.

What I'm looking to achieve is stopping pressure build up which seems to be occurring in the coolant - hence have replaced the cap with an aftermarket one (sold as suitable for the 3.0dci) but is actually for the 2.2dci engine with a lower pressure point. Seems to leak well below pressure though...

I believe Stat is currently locked open (following adding K-Seal).

Good to hear blocks rarely warp - that's good to hear. Do you know if front & rear heads can be removed in situ? I suspect front can but back may be problematic as it's under bulkhead.

With skimming I was concerned about pistons hitting valves (though with so little being removed I wondered why Renault were against it).

I shall retry testing coolant gasses as the behaviour has changed since I originally popped K-Seal in. Originally slow bubbling which rapidly increased when pressing accelerator * indicator fluid went from blue to green.

Now (using water just to detect if gasses generated) it seems to suck in air slowly when pressing the accelerator & release it back when accelerator removed. Very odd. May be something else - can't think what. EGR cooler seemed fine - I pressured the water jacket rather than exhaust chamber but can't imagine that would make a difference - i.e. either way would pass or fail?

JJ
 

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Very interested in the final outcome of this .....................


If the engine etc is mechanically sound then the only way to prevent/stop pressure build-up in coolant is to lower the temperature of the coolant


Replacing the cap with anything lower than what was designed for is bound to just cause loss of coolant (earlier release) and a possible overheating condition (on metal parts) as a result of too little coolant in the system boiling again soon as you release the unwanted pressure generating item (releasing throttle/dropping revs) . Coolant systems generally are designed with an expansion volume adequate to cope with normal temps in the body of the coolant volume and a pressure cap to suit.


I know you are only looking at alternatives or delaying the inevitable ................ just mentioning
 

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Discussion Starter #15
Engine did get hot so replaced with a new cap of the right pressure.

Looking on ebay I see a 3.0dci which has heads skimmed, gaskets replaced at a cost of £2100 and it looks like the same problem has come back. Fault with car being sold is said to be coolant hose burst (symptom I have had caused by over-pressurisation). I assume he has the same fault back after 26K miles and less than 2 yrs.

https://www.ebay.co.uk/itm/Renault-Grand-Espace-3-0Dci-Initiale-2005-for-repair/333212873206

Just to add, removed and tested the thermostat. What a pig to get at. Removal of rad fans required which in turn needs injection computer removing, auto gearbox computer removing plus battery & air pipes.

Stat was fine - thought K-Seal may have caused it to stick open, but no, stat all fine & no evidence of any K-seal deposits. Tested it in water for opening temp etc. All okay.

Refilled system with anti-freeze & more K-seal. Little if any exhaust gasses when cold but when engine warms, gas test shows fluid turn from blue to green in not a lot of time so issue still there.

Not seen anyone successfully come back from this symptom so looks like it's cut your losses time...though I may just have a go at replacing the front HG. in situ. Nothing to lose..

JJ
 
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