306 - blown head-gasket after-effects...

omelette · Unread post by **omelette** » 22 Oct 2010, 01:20

Hi. I have an old '94 Peugeot 306 that has been off the road for over 5 years ('cos I got me a Corolla!) and I'm thinking of getting her up and running again. When running, it had been practically trouble-free for years. The problems started when she blew a head-gasket. Initially I went for a cheapo fix - just replacing the gasket itself! Though up-and-running again, almost immediately I noticed there was far more steam than normal coming from the exhaust than before, presumed my shoddy workmanship to be the culprit, so a few weeks later got a 'new' second-hand head, (it was in far better condition than the original which was quite pitted) had it skimmed and fitted it with a new head-gasket! Problem solved I thought, so imagine my disgust when I found it doing exactly the same thing. It was then I got the Corolla!

Anyway, back to the present day, having had it running for many hours, the problem still remains - quite a lot of steam coming from the exhaust with the radiator level dropping noticeably in a relatively short time. Note that the radiator-fan works perfectly, cutting in precisely when it should, so no overheating.

I'm quite certain that the head/gasket, thermostat, airlocks, or a blocked-radiator are not to blame (having either changed/checked them) so was hoping some engine-expert here could offer an explanation - how is that damn water still finding its way out the exhaust as steam???

Unread post by **Peter.N.** » 25 Oct 2010, 14:35

Sadly it could be that the head is cracked. XUD heads do this for a pastime if boiled - I assume it is diesel.

Peter

omelette · Unread post by **omelette** » 26 Oct 2010, 01:38

Hi, I appreciate the reply. No, it's actually petrol. About the head, as I noted, the 'old' head was behaving exactly the same, drove fine for the few weeks I had it running, just way more steam than there should be. Then I got the 'new' head plus a new gasket - same result, so I'm pretty sure it not the head! If you meant the bit under the head, maybe... It was suggested then by a perplexed but very competent brother (who guided me through the first head-removal) that it could be a cracked piston-liner. (if memory serves!) I even bought one of those compression gauges 5 years ago, stuck it on each cylinder with the engine running only to be told that this was not how you go about it! For what it's worth, one cylinder's pressure was quite a bit lower than the other three. But when the head(s) were off, we had quite a bit of time to examine things visually and nothing seemed amiss...

citronut · Unread post by **citronut** » 26 Oct 2010, 08:13

was this engine fried before removeing the head the first go round,

if so you may well have sunk linners as they should be protrud from the top of the block with the head off, if they are not you will not acheve a gas/coolant tight seal,

what engine is this,

was the head skimed and the matting surface cleaned thoughraly,

regards malcolm

omelette · Unread post by **omelette** » 26 Oct 2010, 20:28

Hmm, good question. I was on a 200 mile trip when the incident occurred. About 60 miles from home it started overheating. About 25 from home I knew things were critical - several times the STOP light came on, whereby I'd pull in for 10min, let it cool before trying again. This didn't get me far at all, so eventually abandoned it and phoned someone for a lift!

Sound fried to you?

The second head we removed at the breakers ourselves so definitely no frying there. It was professionally skimmed and everything was as clean as possible before fitting it.

As I intimated, I was certainly not the brains behind the operation, but my brother has stripped-and-rebuilt more engines than he'd care to admit to - point being, first time round (head-wise) it had his undivided attention and something as in-your-face as a sunken liner would almost certainly have caught his eye. I say "his" 'cos up till then that was my first look at an engine in earnest!

One other thing, after the 'old' head + new head-gasket had been on and running for the few weeks before I replaced it with the 'new' skimmed head, I expected there to be some sign of leakage on the 3 week old head-gasket - there wasn't it was pristine, so much so that I was sorely tempted to reuse it, but was persuaded from doing so...

PS - It is a 1.4L engine.

omelette · Unread post by **omelette** » 29 Oct 2010, 21:46

Just thought I'd add a little addendum to this saga. I took the 306 for a prolonged spin today, about 2 hours driving and the first time it has seen the road in years. Starting off, it was really embarrassing the amount of steam coming from the exhaust - a bit like one of those clown-cars! - but once it warmed up, the steam vanished and you'd never know there was a problem. (at least from the drivers perspective, dunno how noticeable it is from the outside) Also, no overheating whatsoever and on returning home and having let it cool down, the water level in the radiator didn't appear to have changed one iota!. But when I gunned the engine with it sitting there on the drive after arriving, lots of steam came out (or so it seemed) Yet the radiator level hadn't fallen! I'm baffled...

Unread post by **Peter.N.** » 29 Oct 2010, 21:59

What was the outside temperature at the time?

citronut · Unread post by **citronut** » 30 Oct 2010, 08:50

sometimes after a car has had a head gasket failure the exhaust has quite a bit of moisture in it, this can take a few runs to clear

regards malcolm

omelette · Unread post by **omelette** » 30 Oct 2010, 17:49

@Peter.N. - Outside temp was around 15DegC.

@citronaut - I've been hoping it was something like that for the longest time, unfortunately the head-gasket blew 5 years ago and it had a few weeks of heavy driving after the event then. Since, it's been sitting in the drive, periodically being started and let tick over for a half hour or so, so any of the 'original' water should have worked its way out of the system long ago I should think!

Anyway, seems like the water is slowly dropping in the radiator afterall - this morning it was down about an inch, not bad after 2 hours driving but not good as this seems to confirm that there's a leak somewhere.

siraff · Unread post by **siraff** » 31 Oct 2010, 12:21

You really need to do a compression and leakdown test to confirm but it sounds like a liner issue. Either sunk or cracked.

omelette · Unread post by **omelette** » 02 Nov 2010, 23:52

When the weather clears up a bit I'll do a compression test again, correctly this time! Thanks to your search-phrase "leak-down", I've been educating myself as to what it entails. I came across a really great series of videos on youtube by "EricTheCarGuy", very informative. He mentions in the one about compression testing that he also has one on leak-down testing but I couldn't find it. Lots of other info available on the net though - you just got to know what to look for!

Thing is, there's not much I can do if it is a cracked liner. I certainly don't have the equipment or the smarts to do the job myself and it would probably work out cheaper to just swap out the engine itself. And like I said, it drives fine as it is but there's no way that I'd get it through a MOT test - though I'm sure it would provide some amusement for the testers when they'd go revving the engine for the emissions test only to find themselves engulfed in a steam-bank! I don't think I could handle the embarrassment

The irony is, the engine in the 306 is probably in better shape than the Corolla's - though I made sure it had one owner, low mileage, and a complete service history when I bought it, I got stuck with a POS that 'disappears' engine-oil at an alarming rate - it doesn't appear to burn it judging by the exhaust output and it doesn't leak it either!!! But the problem is much talked about on the net (engines manufactured between 1998-2002) though Toyota refused to acknowledge the problem exists.

The 306 engine on the other hand with almost 160,000 miles on the clock never seemed to burn a drop of oil...

citronut · Unread post by **citronut** » 03 Nov 2010, 13:25

you wouldnt neser celaly see a sunk linner as its only thous we are talking hear, you need to place a straight edge across the top of the block and each linner one at a time, then mesure the gap between the straight edge and the top edge of the block, then you will get the amount the linner pritrudes from the block,

regards malcolm

omelette · Unread post by **omelette** » 03 Nov 2010, 17:44

Damn, I didn't think the tolerances were that high - we definitely wouldn't have noticed that! So I guess the next job would be a check like you've outlined. I appreciate the info.

I actually did a compression test today, each cylinder check twice, then averaged; -

Cylinder 1: 155 psi.
Cylinder 2: 172 psi.
Cylinder 3: 160 psi.
Cylinder 4: 165 psi.

This is presuming I'm right in thinking that cylinder 4 is the one next to the cam-shaft sprocket - Haynes' manual is a bit vague for my liking. It also states that there's no Peugeot-supplied compression figures available, but anything below 10 Bars "can be considered as less than healthy" - weee, all of my cylinders are above this, 11 Bars or more!

Gotta admit though that I've also just read that the test should be done with the engine fully warmed-up - the above figures were produced with it stone-cold, so I guess I need to do it again...

citronut · Unread post by **citronut** » 03 Nov 2010, 18:55

you should also disconect the coil and if the car has a cat disconect the injection relay, this is the prevent unburned fuel being pumped into the cat, and the coil to make sure you dont knock out the ignition module,

whilst cranking over for a compresion test hold the throtle fully open,

regards malcolm

omelette · Unread post by **omelette** » 03 Nov 2010, 22:43

Yeah, I had disconnected the coil but Haynes' bit about earthing after disconnecting seemed over-kill and confusing. It has a catalytic converter but never heard of an associated "injector-relay". I also was holding the throttle full-open during the test and expected it to be flooded when I tried starting the car but it started first tip, which is unusual - it normally turns over for a second or so before starting. I put it down having decreased the spark-gap on all of the plugs, which have become quite worn and really need to be replaced...

Speaking of which, when I removed them, I noticed 'residue' of sorts on one which I haven't seen before, so took a few pics - no. 2 from left is a funny colour. Does it reveal anything?

http://ubuntuone.com/p/NeV/
http://ubuntuone.com/p/NeW/

PS - Images can't be uploaded here (boo!) and links to images don't appear to work right either - links don't come up as being active...