Peugeot 308 CC - Leaking again!

[GiveMeABreak]

Yes, I thought you meant only the spare had a sensor. As per the factory spec., TPMS wasn't fitted, so I suspect these are non-OEM aftermarket ones that have been fitted - but without the monitoring unit (usually dash mounted) they won't do much. The OEM ones would not be fitted if not part of the original trim / spec. due to cost, so I can't think of another reason apart from the aftermarket option or id the whole set of wheels were purchased to replace the originals, which may have had TPMS fitted - and then it would be an additional cost in time and money to remove these and fit normal valves. So they probably left them on knowing they wouldn't work without the receiver and the configuration.

[van ordinaire]

You'd think a tyre shop would be able to fit a battery, as most of them sell them.

Anything with the battery UNDER the back seat would confuse most folk these days.

Loading VW T3 & 4 estates was also guaranteed to gain passing interest, if not a small crowd.

[xantia_v6]

All PSA models are very rare here, so a typical tyre fitter has probably never seen under the bonnet of anything with a layout like the 308. And it is difficult. The air intake resonator needs to be removed. Then the fuse tray above the battery cover must be unclipped and moved aside, but there is no visual cue as to how that is done, and it requires an amount of force that always feels near the breaking point of the plastic. Then the battery cover must be extracted in an awkward manoeuvre (not as difficult as getting it back into the right place).

The wheels on the car are genuine Peugeot of the type that this car was fitted with at the factory, and I believe that prior to my ownership it never had anything done except by the dealer.

[Zelandeth]

You'd think a tyre shop would be able to fit a battery, as most of them sell them.

Anything with the battery UNDER the back seat would confuse most folk these days.

Loading VW T3 & 4 estates was also guaranteed to gain passing interest, if not a small crowd.

Here's the compartment it lives in - usually hidden under a plastic cover and with a thick sound deadening mat on the floor too.

Could fit a decent amount of stuff back there too.

The little hatch in the floor gives access to the gearbox oil filler/level cap (you dip it using the engine oil dipstick to check the level) and clutch slave cylinder adjustment.

[xantia_v6]

A few days ago, I noticed a few drops of coolant under the front of the 308...

It was not immediately obvious where it was coming from, it was near the front of the engine, which normally rules out the thermostat housing, which tends to drop coolant from the rear of the engine. Previously leaks near the front have been due to poor clamping of the hoses to the transmission oil cooler or the radiator.

I fitted my cooling system pressure tester and pumped it up to 1 bar, and sure enough, after a couple of minutes, coolant started dripping under the engine, but it was not clear where it was coming from. It was clearly not any of the previously mentioned parts, as it seemed to be dripping onto the catalytic converter lower mount from somewhere obscure higher up on the front face of the engine behind the turbocharger.

Some internet searching revealed that the THP engine has an engine oil cooler mounted on the oil filter block with the coolant entering via a direct passage form the block and exiting via a hose to the turbocharger coolant pump. The rubber seals between the engine block and the oil filter support, and the seals between the oil filter support and oil cooler are known to go hard and leak.

All very good to know, but it transpires that to replace the seals, it is necessary to remove the catalytic converter to gain access to the screws that secure the oil filter block. In the confines of the space behind the radiator, it is not fun at all. Removing the radiator would make the job more pleasant, but to remove the radiator you need to remove the top mounting screws that for no good reason are positioned such that you would need to remove the front bumper first... so much for that idea.

I got the job 75% done yesterday. I hope that the leak is fixed.

[xantia_v6]

I got it reassembled today, no great drama, but still an awkward job. As an aside, this version (the THP 156) does not actually have an oil cooler fitted, there is just a bypass plate that carries the oil and coolant from one side to the other with no real thermal coupling. The heat exchangers form the higher power variants would obviously bolt straight on.

[xantia_v6]

Six months later it is leaking again. This time it is the oil feed pipe to the turbo which is leaking at the top banjo. It is a very common failure point on these engines, but repair requires replacement of the pipe, as the failed o-ring is crimped inside the banjo to pipe joint.

The really annoying thing is that all the disassembly I did last time (heat shields, catalytic converter etc) has to be done again to access the bottom banjo on the pipe, allow 5 hours work.

The replacement will also fail in a few years because the top fitting gets too hot for the grade of o-ring that PSA use, not helped in our case because we live at the top of a reasonably steep hill and the turbo is always toasty hot when we switch off the engine after arriving home.

There are after-market hoses available (the best known is by Detroit Tuning) which eliminate the troublesome o-rings, but I am not sure that I can wait for a part to arrive from the USA.

I have temporarily wrapped the leaking joint with epoxy putty and will see how it fares over the weekend.

[xantia_v6]

It looks like the temporary wrapping has stopped the leak, or at least is holding the pipe in a position where the o-ring is holding back most of the oil. So I have ordered a conversion kit from the US, which should be here in a week or two...

[white exec]

Sounds a grim bit of design, Mike. As you say, turbo/exhaust is not a good location for any sort of flexible O-ring. What were PSA thinking of?

[xantia_v6]

Here is a cutaway of the original fittings:



This is the replacement that I have ordered:



It would be only a bit irritating except for the 4 hours labour to change the part.

To make the design even better, the factory fitted a little heat shield, but instead of putting it between the turbo body and the pipe, they put it on the other side of the pipe, so that heat is reflected back onto it from what would have been the cool side.

[white exec]

Crazy

[CitroJim]

The replacement you have ordered looks better engineered Mike...

Hopefully, once fitted, that'll be the end of your problems in this area...

[xantia_v6]

The hose kit arrived and has been fitted. It is certainly no longer leaking at the top end, you can't see the bottom end (behind the catalytic converter heat shield), but there is no longer a smell of burning oil.

Tomorrow we are off for a short holiday in Invercargill and Queenstown, so a good run to test the oil-tightness.

[CitroJim]

Tomorrow we are off for a short holiday in Invercargill and Queenstown, so a good run to test the oil-tightness.

Enjoy the holiday Mike