Peugeot Forums banner
1 - 20 of 26 Posts

·
Registered
Joined
·
20 Posts
Discussion Starter · #1 ·
Hello good people!

I've got a good one for you.

So, my 307 (1.6HDI) had a head gasket failure back in November. Once the head was off you could seee that, yes the gasket had failed, but the piston liners on two cylinders had also cracked around the tops. So (given that I was already so far intot he job) a replacement engine was sourced.

The replacement engine got its head stripped off and cleaned up. All new gaskets, etc. Engine put in the car, beautiful.

I've now been struggling to get the cooling system right for some weeks. First I had problems with the radiator leaking. Then I could get the air to bleed properly out of the heater matrix. Now all the little leaks and issue have been sorted, the cooling system appears to either loose water, or gain pressure. for example, the car was sitting unused while I was on holiday for a week. When I unscrewed the expansion tank cap, the pressure in the system rushed out and it spat water over itself. Other times you look at the level and it looks as though theres bearley anything in the system, even though it was filled properly before the drive.

The engine oil is all clean, showing no signs of water (eg head gasket leak). There is no white smoke from the exhaust (eg head gasket leak). The system clearly holds pressure.

I cant get my head round this one. Anyone seen this before, or got any ideas?
 

·
Premium Member
Joined
·
2,981 Posts
Was the car sitting in extreme heat conditions when you checked the coolant system? Perhaps the thermostat is playing up? Water pump history i.e how old. Being a new to you engine there could be a dark history with it? Try compression check of the cylinders to see if there is a problem there.
 

·
Registered
Joined
·
20 Posts
Discussion Starter · #3 ·
Was the car sitting in extreme heat conditions when you checked the coolant system? Perhaps the thermostat is playing up? Water pump history i.e how old. Being a new to you engine there could be a dark history with it? Try compression check of the cylinders to see if there is a problem there.
Hey! Thanks for the reply!

No, no extreme heat - dude the weather this year has sucked!

When I swapped out the engine, I really only used the "new" block. All other components came from the old engine (water pump, timing gear, head, etc). The oil pump was new. The old engine had all these bit replaced recently, so seemed to be the lower risk option.

The water pump is a possible culprit, although I'd expect to see water being dropped?

Thinking back a bit further (its hard!) the old engine had started to have coolant issues before the head gasket went. It was loosing coolant, but not everheating. No clue as to where the coolant was going, no tell-tails. I assumed, after the gasket failure, maybe wrongly, that the route cause was tha the headgasket was on its way out. Given that my current issue seems very similar, I'm wondering if the issue could actually be the head?

Not really sure how a head could do this. Possibly a crack somewhere? Valve guide?

Loving the thought of taking the head off again!
 

·
Registered
Peugeot 4007, 2013.
Joined
·
183 Posts
When the engine isn't hot, take the radiator cap off and run, have someone bring the revs up a little and hold, about 2-2.5k RPM. Watch for air bubbles, see lots, you may have another headgasket issue / crack or even lose headbolts. See a few, and you may have a pump or other leak to find.

Do NOT do this with a HOT Engine, the water can flood / steam out, and it will burn you. It is a quick test (under 5 minutes), give you a general answer quickly without any special equipment.

Hope you find this helpful.
 

·
Registered
Joined
·
20 Posts
Discussion Starter · #5 ·
When the engine isn't hot, take the radiator cap off and run, have someone bring the revs up a little and hold, about 2-2.5k RPM. Watch for air bubbles, see lots, you may have another headgasket issue / crack or even lose headbolts. See a few, and you may have a pump or other leak to find.

Do NOT do this with a HOT Engine, the water can flood / steam out, and it will burn you. It is a quick test (under 5 minutes), give you a general answer quickly without any special equipment.

Hope you find this helpful.
Never heard this before, thank you!

Gave this a try. I didnt see any bubbles coming up through the expansion tank, but the level was pitching around quite a bit. Interestingly, the coolant level rose during the test. It started out at the fill line (the moulding split line) and ended up a good 15mm(+) higher. Less then 5mins of run time from cold. The level did not drop when the engine was shut off. As i write this, the car has been sitting outside, engine off, for around 15mins (post test) and the coolant level remains the same (~15mm (+)) higher than when I started.

That's not normal?

Also noticed that the inside of the expansion tank has a film of black dirt stuck to it. It rubs off if you give it a finger. The expansion tank was new, squeeky clean less than 2k miles ago.

I'm still leaning towards a head/head gasket issue. Not saying that I necessarily understand it.
 

·
Registered
Peugeot 4007, 2013.
Joined
·
183 Posts
OK, good test results.

The churning is normal, that's from the water pump doing its job. And the expansion of water is also normal. That's why you have expansion tanks.

The black film, was well worth noting, as this gives me missing information to take a good guess at the issue. Have a look at the under side of the radiator cap & it's condition, that maybe the source of the black. The cap and/or the spring may have been stressed from the previous problem and not playing well now. It is supposed to let out the pressure, but too weak and start letting out your coolant. The overheating from prior engine head-gasket blowout may have weakened the spring in the cap.

A way to test, my theory above, put the overflow from the radiator cap, into a suitable container to catch, in safe position if possible, and go for drive and see if filling the container. A radiator specialist can test the cap pressure or can just buy a new one if you think this is the issue as well. Aftermarket are ok, don't need to go OEM.

Hope you find this helpful.
 

·
Registered
Joined
·
20 Posts
Discussion Starter · #7 ·
OK, good test results.

The churning is normal, that's from the water pump doing its job. And the expansion of water is also normal. That's why you have expansion tanks.

The black film, little worth noting, look at the under side of the radiator cap & it's condition that maybe source issue. The cap or the spring may have been stressed from the previous problem and not playing well now.

A radiator specialist can test them or can just buy a new one if you think this is the issue as well.
Thanks for the quick reply!

The cap is also new, this was replaced along with the expansion tank. Course, that doesnt mean the cap isnt faulty, and it wasnt a genuine Peugeot part.

Got the cap in my hand now, I can see that its got marks around the bottom where its been spewing.

(Expansion tank coolant level is still the same - ~15mm(+) from where I had topped it up to. Surely I would expect to see that drop by now?)
 

·
Registered
Peugeot 4007, 2013.
Joined
·
183 Posts
The engine takes a long time to cool down, if you want to wait, about 5 hours should normalise to the level you have seen. Why you fill when cold, can get more in there, and the bonus does not burn you !

A air leak into the system from a pipe/seal might cause what you are seeing but there should be some fluid loss, even if evaporates, say dropping on hot engine part you can normally see or smell it (sickly sweet smell)

Good they replaced the cap and expansion tank, whoever did the work for you were quality, might be worth asking them to look again at it or a radiator specialist ?

If it was head-gasket that test would have water pumping out, or stream of bubbles to air pops, here are other general tests and the one I mentioned
 

·
Registered
Joined
·
20 Posts
Discussion Starter · #9 ·
The engine takes a long time to cool down, if you want to wait, about 5 hours should normalise to the level you have seen. Why you fill when cold, can get more in there, and the bonus does not burn you !

Good they replaced the cap and expansion tank, whoever did the work for you were quality, might be worth asking them to look again at it ?
The engine takes a long time to cool down, if you want to wait, about 5 hours should normalise to the level you have seen. Why you fill when cold, can get more in there, and the bonus does not burn you !

Good they replaced the cap and expansion tank, whoever did the work for you were quality, might be worth asking them to look again at it ?
Thanks again for the quick reply.

I did the work on this bad-boy, no one to make responsible other than myself, sadly! I'm going to try the cap off our other car (The Bus)(Citroen C4 GP, same engine), see what that does. Also going to leave the car alone for the day and just see what the coolant level does - just interested to see.

I'll let you know whether The Buses cap does any good.
 

·
Registered
Joined
·
20 Posts
Discussion Starter · #11 ·
Well your quality then ;) and you can quote me on that.

I do all my own work as well.
I'll take that :)

Its all good until you hit a wierdo problem (like this one). This form, and you excellent folk within it, are proving to be extremely helpful though. Really appreciate it! (y)
 

·
Registered
Joined
·
20 Posts
Discussion Starter · #15 ·
Okay, been out for a quick run in the car (Bernard!) today with the other expansion tank cap on (cap from our other car). I can definatly say that Bernard shot his load out of the expansion tank during the 5min drive. Now that I'm looking out for it, I can hear the sound of it releasing pressure while I'm driving. Still not overheating though, he stays at a constant ~70 (assume thats Degress C?) on the dial.

On my return home, the expansion tank is now completely full of coolant, almost right up tothe top. The sound proofing overthe top of the wheel arch is wet from the over-spill.

So, with the thermostat, would we be assuming that it isnt opening up, and therefore the car is (effectively) boiling over?
 

·
Premium Member
Joined
·
2,981 Posts
A great possibility but does not necessarily answer the sudden return of the lost water you mentioned earlier. As you replaced everything else I would replace the stat along with a reverse flow pressure cleanse through the block and heater with heater on hot just to ensure there is no block blockage build up.
 

·
Registered
Joined
·
20 Posts
Discussion Starter · #17 ·
A great possibility but does not necessarily answer the sudden return of the lost water you mentioned earlier. As you replaced everything else I would replace the stat along with a reverse flow pressure cleanse through the block and heater with heater on hot just to ensure there is no block blockage build up.
Picking up a new thermostat tomorrow. I'll come back to the string with the results.
 

·
Registered
Peugeot 4007, 2013.
Joined
·
183 Posts
If air is entering the system or present, the temperature you need to watch very carefully, as depending on where the sensor is located air pockets will provide false reading of actual temperature of the coolant.
 

·
Registered
Joined
·
20 Posts
Discussion Starter · #19 ·
Okay, well for a brief moment, I though we had it. I changed the thermostat (tested the new one before putting it in!), and flushed the system through. Sadly, the system is still exactly the same. I also tested the old thermostat for good measure, sadly that worked nicely too.

Sooo, yeah, I'm out of ideas again. I think I'm back to a cyclinder head/gasket issue. Note, I still dont understand it.
 

·
Registered
Peugeot 4007, 2013.
Joined
·
183 Posts
If you are revisiting the head.

Here are things I would think about.

Head itself, was it replacement, did you check for warping, was it machined.
Head Gasket, did you torque it correctly, in at least two stages to final torque, following a pattern recommended, using new bolts or if old making sure the were clean and free from oil and threads were all clean, no gunk.

Any coolant carrying seals were replaced, if they mate with gasket, ensure they are both true and flat when mated to each other without the gasket. I always use Loctite Aviation Gasket Sealant No 3 with gaskets on the cooling system.

Hope you find this helpful.
 
1 - 20 of 26 Posts
Top