Long Term Coolant Leak (Air Lock?) Problem

[Grim.Badger 15]

Well it wasn't the inlet manifold Put everything back together, tried to start it, and coolant shot out of the expansion tank. Took the plugs out and one of the cylinders is full of coolant again.

 

I had done a compression test:

 

135 - 180 - 140 - 195

 

The one in bold is the knackered cylinder. Whilst this isn't great, it's more or less the same as the last test I did a couple of years ago, so I'm not sure what's going on.

[welshpug 1,622]

its fairly clear to me! its a gasket or liner issue, or head corrosion.

[Grim.Badger 15]

its fairly clear to me! its a gasket or liner issue, or head corrosion.

 

Sorry, it had been a very long day. I meant there was no obvious, definitive, problem but it is clear that the head needs to come off - if I decide that the car is worth salvaging at this point (it's not in good shape generally).

[steve@cornwall 100]

How did you seal the manifold to head? As Anthony says above it may be a bit too far gone for gasket alone. I've never had any problem using silicone sealants in place.of gaskets here and put a healthy bead into the waterway too for good measure. And not forgetting to give it time to cure too before starting the car. As said head gasket isn't hard to do, I had to do a bit of an emergency h/g change a few years ago when I was both short of time and stony broke, no skimming, no new head bolts, just cleaned the surfaces , fitted gasket and reassembled and have done almost 20k without incident since.

[dcc 855]

I bet you filled a bore when you took the inlet off

 

Off with it's head!

[welshpug 1,622]

I find gaskets work far better on metal to metal joints than silicone.

[Telf 222 2 Cars]

I had similar problems last year- engine stripped due to an over fuel fault, rebuilt and had a leaky inlet manifold.

 

One of the bores managed to fill with coolant so I hand cranked the engine to push the fluid out, then got annoyed and just started it with a plug out- that blew the excess clear.

 

The inlet manifold had minimal corrosion but it still after cleaning needed a gasket and a good amount of hylomar sealant to stop the leaks.

 

Are you 100% sure the reading s on the cylinders are correct- I had a long tiring day and tried a compression test- the initial readings I got indicated a knackered cylinder but subsequent retest(once I'd calmed down!) showed them to be ok.

[DamirGTI 325]

Do an 'block test' !! it's cheap and very precise for diagnosing such problems with blown HG , cracked head , cracked liner etc.

 

D

[steve@cornwall 100]

I find gaskets work far better on metal to metal joints than silicone.

Can't disagree that using the correct material for any job is preferable, but the gaskets aren't desiged for fitting between two damaged surfaces and may not be pliable enough to seal the imperfections. And I'd rather risk wasting an hour or so against pulling off a head which may not need it, no matter if the sealant will last long term. Even if done for purely diagnostic reasons.

[toolie72 67 1 Cars]

Manifold off-accept you'll loose coolant out of head holes, turn it over

Would be really messy but if cylinder filled up again you'd know it wasn't manifold therefore it's head

(block head to manifold holes of with something might be less messy lol)

Might be worth a try-if it's the head then at least you'd have manifold off and have more room

[welshpug 1,622]

40 psi down on one cylinder, and you think its an inlet manifold leak?

[steve@cornwall 100]

Well......the cylinder filling with water is not the lowest for compression, so no I don't think a manifold leak is the only problem here. However I do think it's possible, if not likely, that a manifold leak is causing the cylinder to fill with water which seems to be the immediate concern as does weighing up wether or not the car is worth repairing in the owners eyes.Baring in mind the pressuring problem is long term (pointing to h/g failure imo) and has been lived with up until now I would have thought it worth investigating. Personally with the same circumstances I'd most likely try the manifold with plenty of sealant, then a head gasket replacement and if that didn't sort it , a good replacement engine.

I'm in no way suggesting it's not right and proper to investigate the head gasket, liners, block and head integrity etc just wondering if that is feasible in this case.

Personally I wouldn't go to the expense and trouble of what is basically a full engine rebuild in my own car, it's just not worth it with the overall condition of my car, but I would try to keep it running and driving by more modest avenues at all possible.

Just an opinion and an alternative approach

[toolie72 67 1 Cars]

At the end of the day if heads gone its gone-simple as that-no amount of snake oil/real steel/whatever will fix it-head has to come off

 

Not a difficult job-easily doable even outside-just a pain in bum

Did my head gasket in 1997(first time) and was terrified (first overhead cam I'd done) but much simpler than I thought it would be

 

I do agree that all possible causes need checked first, I personally don't have any concerns about using a dab of instant gasket (although I've seen some engines "rebuilt" with it)-we used to build automated assembly machines and they should have been sponsored by the loctite range!!

 

On a side note Peugeot parts dept circa 1997 stated that new head bolts were NOT required (I change them anyway)

Worst case you take head off and engines scrap-relatively easy to change-other than lack of space and finding other bits to do lol

[Grim.Badger 15]

It's definitely not the manifold-head joint causing the current problem. When I said that coolant shot out of the expansion tank when I tried to start the car, I meant shot out. It pushed out about a litre of coolant in less than a second, like "Old Faithful." There is also most definitely exhaust gasses coming out of the coolant system now, which there didn't seem to be before (there was vapour, but it didn't smell of exhaust, but that could have been my poor sense of smell).

 

I have a spare engine, but it's been sat for about 8 years so needs a clean and thorough check. I may take the head off the current engine just to see what went wrong anyway.

 

Edit: I suspect I've had a small crack or warp somewhere for a long time, and replacing the expansion tank and having a fully pressurised system for the first time in years has opened up the crack/warp much more.

Edited June 24, 2016 by Grim.Badger

[steve@cornwall 100]

May still be "just" the head gasket.....ever the optimist.

[toolie72 67 1 Cars]

Take head of first

Less to remove later anyway-if gaskets ancient it'll be like a doily and you'll wonder how it ever worked

NB if you've put snake oil stuff in coolant before it will be sitting in block blocking water flow-my last engine had a crack, put "repair" stuff in until I got a replacement, end result the first block was full of sh@t (made me pull my finger out of my ar@e tho hehe)

[Grim.Badger 15]

Two and a half hours work and the head is off, and it's a mess in there. Despite being Pitcrew, this is the first time I've taken a cylinder head off, so I'd be grateful for any opinions on how bad it looks! The HG was meant to have been done about 8 years and 60k miles ago by the last owner of the car iirc.

 

The cylinder head:

 

 

The bottom end with gasket still in place:

 

 

Close-up of the offending cylinder and gasket:

 

 

The gasket:

 

 

Bottom end with the gasket off:

 

 

Side shot of the encrusted liners:

 

[toolie72 67 1 Cars]

Is the fire ring (as I would call it) bust on pics 2&3?-looks like it is from photo, that would explain the coolant pressurising (the blow) and the cylinder filling up (on the suck)

How many double entendres is that?

[Grim.Badger 15]

Is the fire ring (as I would call it) bust on pics 2&3?-looks like it is from photo, that would explain the coolant pressurising (the blow) and the cylinder filling up (on the suck)

How many double entendres is that?

 

Just checked it now (I didn't have time on Sunday, had dinner to cook!) and yes, the ring has corroded through and split. After drying the gasket looks even more knackered!

I think that's just two double entendres, depends on "fire ring"

 

Edit: Photo of the gasket (break has been opened up to make it more obvious)

 

Edited June 28, 2016 by Grim.Badger

[Telf 222 2 Cars]

Doesn't look to bad, clean the whole lot up, fit new gasket - sorted.

 

Be careful not to let any krud get into the oil ways - I managed to write off a cam years ago on a 1.6 through poor engineering hygiene.

 

Not sure if it will need a skim- did it over heat? Is there any corrosion on the face of the head?

 

I know most people do it regardless whilst the heads off.

 

Also if your feeling adventurous you could clean up the valves, do the seals, shims etc-(I'm sure you know all that though) so exciting!

[steve@cornwall 100]

Seen much worse gaskets than that come off and all be fine after a new gasket. You'll see much more when the surfaces are cleaned up and corrosion (or lack of it) will be much more apparent. Is the rusting in the cylinder just surface discolouration or is it pitted?Has it been run without antifreeze by any chance?

As for skimming I guess it depends wether you want to chance having to redo the job .When I last did one in a 205 the cost was the main concern so I risked the cost of a gasket and fitted it all up as it stood and to date it's been fine for several years and thousands of miles. More recently I did the same with a 306, because it wasn't worth the time or effort of doing it properly (although I did use new head bolts on that one)

 

Conversely the last time I did one on a car I was going to sell I had it skimmed, New bolts, cam belt and water pump etc because I think there is a fairly good chance it may fail, working out the acceptable odds can only be done by you.

[Grim.Badger 15]

It didn't overheat, despite puffing lots of white smoke It always surprises me how rugged these engines can be!

 

The head bolts are three different lengths, so probably no good to use again.

 

The "rusting" in the cylinder may just be evaporated coolant (its an orange cooalnt I was using) but I'm not sure, I'll have to try to clean it up this weekend and see. Both the valves and pistons are heavily sooted, far too heavy for me to be able to see any damage/pitting, so they'll have to be cleaned as well. As I've now got a second car, I may look into getting the engine done up properly. It was a great little engine, even with its dodgy compression, so I'd like to see how good it is with a decent overhaul. I'm also not sure if I disturbed the liners, but I'd like to pull them out and check them for corrosion anyway. My funds are very limited though, so I'll have to give it some thought. I do have a spare 1.6 engine though, that was working when removed, so I should be able to put together at least one working engine (famous last words?)

 

I'll be removing the rest of the engine this weekend, to give the engine bay a decent clean and de-rust, as it's absolutely filthy from a couple of oil leaks I was very slow at fixing, and quite rusty.

[welshpug 1,622]

if the liners and seats are good you can do a full rebuild for not a significant amount.

[steve@cornwall 100]

You could fit the spare engine and see what it's like? If it's still serviceable you can then rebuild yours at leisure. I bought a job lot of parts for a tenner off ebay years ago which included the lovely engine now in my cti.That had lain in the back of a workshop for many years too and has been one of the best 1.6 engines I've had.