Oil eak - could turbo fail?????? HELP

[harrywy]

Hi

Am new to this and ive bought my first Pug 406 2.0 HDi on a 2000 - ive had her for about 4 months now and been running ok not any issues other than the temp not staying warm.....but ive lived with as I didnt pay much for her and use it as a work horse and does a good job.

I was reading one of the posts about the turbo gone by Supa.........

The pipe from the top of the intercooler to the maifold - I took it apart today as I was changing my thermostat and firstly no thermostat (a bit worrying!!!) and secondly there is some oil in the pipe - but the power is fine no issues with it...

I did and oil change recently and used GTX magatec semi synthetic as it was reomended but didnt know about disconecting the injectors - i just turned the key and let go just before the car fired up. I was going to flush it forst before i changed the oil but totally forgot - some guys on here think its not a good idea to flush it but some do....what are the pro's and con's??

On a petrol engine i used to just remove the fuel pump fuse so the engine would just turn and let the oil pump get to work.

But in this 406 HDi case it was my first oil change on it so hope this didnt damage it....

Also When i had the cambelt changed i noticed oil on the back of the engine where the turbo is and also there is defo oil leak somewhere as there is loads of oil under the car....!

The mechanic just said dont worry about it its prob your oil seals - not much you can do till they go an have then got to be changed or something......dont know enough about these cars.....

Any thoughts on this???

Your help would be much apreciated.....

[djheath]

I dont have many thoughts, but I do have a few, so here goes!:d

No thermostat. Hmmm well that would explain why you have little heat with all the coolant going straight to the radiator before it has got warmed up. I know people usually take out the thermostat to cure a over heating engine problem so keep an eye on the coolant temps when you replace the thermostat as it may indicate a blocked hose somewhere or other problems.

Thats the first I have ever heard about letting the engine turn over after doing an oil change, but I can understand the logic. I personally have never done that and just refilled the engine with oil, started her up and driven on my my way.

Flushing oils. Hmmm some people say its worth using them cause they clean all the crap out of the oil galleries, but others say that the crap sometimes helps to seal holes and joints which have formed over the years. After using the flushing oil, you clean all this sludge out and the seals and joints suddenly start leaking. Dont know how true or likely this is!

I am a petrol man myself, so cant help with your turbo questions.
Thats my two pence worth there.

Hope it helps.

[harrywy]

Thanks for your reply,

Am a petrol man my self too, ive turned to the HDi to cut on fuel costs but still have my M3 which i only run on the weekend....

I understand both sides of the logic for the oil flush.....maybe some more experienced guys on here would have more of an insight to this debate.....

I was shocked there was no thermo so ive used rad flush and changed the coolent - well ive managed to take the water out of the rad... I wasnt too sure in how to drain the engine.....

Does anyone know how I can do this??

[DaiRees]

Hiya mate, another petrol man here so still not a lot of help.

Yeah the argument about engine oil flushing was exactly as djheath says. The crud helps the seals, and when you remove the crud you do more harm than good. The upshot from our resident mechanic at the time seemed to be that if you've always flushed it, keep doing so, and if you've never flushed it it's probably safer not to start flushing your 8 year old engine now. I'm not convinced by that argument myself and would probably flush it anyway, but then again I've had mine since nearly-new and I flush it every time I change the oil. Of course having just bought the car you've no idea if it's been flushed in the past or not .

Be careful if you've changed the coolant. I believe that correctly filling and bleeding the HDi coolant can be a bit tricky. Have a look at this. Try a search on here more more info.

[harrywy]

Hi

before i changed the stat i took of the botton pipe (have to release tap on the rad) then took the top pip off and removed the housing. since there wasnt a stat in there i decided to use some rad flush - so i put the pipes back together and filled her up let it run to temp on idle opened the bleed valve on the rad once water started coming out of it - closed it up and closed the rad cap. let the engine run till the fan kicked in.

I then let it cool(learnt in the past the hard way) - opened rad cap and bleed valve - removed bottom pipe and top pipe - let the water out (looked like just water was coming out so all/most antifreez would have been taken out). New stat went in with seal and closed her up.

I think i should have filled her up with the engine running but instead i filled it up first and then started her up - not sure what this will do but ive been runnig the car now for a day and there hasnt been any loss of water or overheating - but will keep any eye on this.

If there is something ive missed or need to do please let me know guys.

Thanks for the replies so far...

[Longintooth]

Hello Harrywy
You sent me a personal email and I believed you were refering to the turbo arrangment not the water coolant. If you are talking about the water coolant then this should have a thermostat but the turbo system does not. If you are not familiar with intercoolers then you are probably confusing the pipe coming out of the top radiator on the right hand side with the water coolant radiator - they are completely seperate - the one on the right is for charge air cooling.

For the benefit of others on turbos. Great care must be taken to ensure oil is always at the turbo bearings before starting whether petrol or diesel so after an oil and filter change where the oil gallery is drained it will take a few seconds to fully recharge and expell air from the whole system. Just a moment of dry running will have an effect on the seals and bearings albeit not apparent in the short term. The turbo works in a very harsh environment and the importance of the oil quality and use cannot be stressed enough. Putting low grade flushing oil through even for just a short run up will have dire results on the servicability of the Turbo seals and bearings it's akin to dripping parafin on a hot plate - it evaporates in an instant. As I stated in my email to you likewise ensuring that you let the turbo cool off after a hard run is more important than other issues but as you will note it is the culmination of all the points I mentioned that ensures your turbo will give you a satisfactory long term service.
Regards

[mbell666]

When i change oil i just fire it up and let it idle till oil pressure light goes of anf turn off, then check level (after a little while).

You drain the coolant out of the engine from a bolt somewhere on the block (rear i think). pretty tricky to find i think.

Quite normal for the KKK turbos to leak bit of oil (Welton has posted pics of his before) alot of HDi do it. Normally sign the oil seals are warn but not a major problems. Turbo failures on the HDi are pretty rare. Unless it losing a lot of oil don't worry about it and don't bother replacing the turbo.

[Longintooth]

Hi
It is not a normal or intentioned occurance for oil to leak from anywhere -it is a fault and should be rectified not to do so is reckless and makes a mess in your drive way, in addition it is costly to keep your engine topped up and every drip on the highway creates a hazard for other users. That aside small weeps do occur and the decision to act is when it is dripping. I know lots of people ignor good practice and just do their own thing that does not mean others should follow like leamings off the cliff.

Moving on - if an engine has been overheating it is one of three reasons - low on coolant, faulty thermostat, but more likely the tubes in the radiator core are blocking up and no amount of flushing or chemicals will free them out, this is because once the tubes block up the flow of water can never get going again, even to take chemicals through. they block up mainly where the air flows through in concentration ie around the fan area this causes the chilled water to sludge up. What happens is the cooling area of the radiator starts to shrink. To avoid this "good practice" would be to ensure you flush out the coolant at least every two years and ensure that the coolant antifreeze/inhibitor is correct for the vehicle. This is very important with todays engines since there is a different mix of alloys in blocks and heads and also catalytic convertors and lambda sensors can be damaged if they come into contact with coolant inhibitors of the wrong sort. Oh and hoses never get blocked - they are too fat. Oops I missed another cause - if the radiator pressure cap is faulty then the coolant can boil off under reduced pressure about 3 degrees per lb/sqins. So if the engine runs at atmospheric pressure it will boil at 100 deg C by raising the pressure to some 20 lb/sqin the boiling point rises to 20 x 3 = 60 degrees a total of 160 degrees before it can boil. That is why if you ever foolishly remove a radiator cap when it is hot you will incurr 3rd degree burns as the coolant then boils instantly forming a columb of water about 300cms high - just the right height to scald your hands and face.
Ignorence can be bliss but seldom is.

[Welly]

Hello Harrywy!

I'd say yes to oil flushes - mines allways had one from looking at the service invoices so I just kept up the practice!

Removing the thermostat is either someones previous f*ck up which got left alone/forgotten or it's a sign that it was overheating

Keep checking the rubber hoses (now you've fitted a stat) for signs of overpressure, the hoses tend to blow off on the HDi if you're running excess coolant pressure. Worse case is that the head gasket has gone due to previous low coolant levels but I'll keep my fingers crossed for you

My turbo is covered in oil but boosts away like a good'un

[Longintooth]

Hi
Flushing oil use started in the early centuary when oil was produced as a very bare substance, over the years it has become liquid engineering and performs many tasks which early oils could not do then. Todays oils maintain all the nasty chemicals produced by the engine (Petrol and Diesel) in suspension which means there is absolutely no gunge capable of sticking to any surfaces inside the engine and this also means decoking of engines has practically been eliminated. I have been involved with heavy diesel engines for years and it is amazing to see the pristine condition of all internals, pistons, rings, cranks, valve gear after thousands of miles pulling 45 tonne and some badley neglected. The oils have additives in to combat extreme pressures,temperatures and remain at the stated viscosity over very long periods. This kind of quality is not inherant in flushing oils and as I pointed out the turbo seals and bearings are susceptable to extreme heat as the exhaust gases pass over the rotor vanes and housing this heat is conducted very quickly down the rotor spindle and to the seals and bearings instantly and unless there is oil flowing at a specific rate over them they will sustain small but gradual deterioration - the ball races will soften and the seals will melt in extreme cases. It is not enough to say well they are coated in oil so they are ok - this coating will burn off in an instant even with the best oil. It must be flowing fast and with the best oil to get the most out of them. Welton is right in saying that an oil covered turbo will run fine but a look inside the charge hose will tell its own story as the seals get worse and this is also confirming what I,ve been saying since he uses flushing oil !!! Many of these myths are perpetrated by unqualified fitters based on long outdated technology.
Oh and fitting a thermostat will not increase the coolant pressure - this is regulated by a pressure relief cap or valve and if the head gasket is leaking, water loss will be the first sign and lack of pressure more likely as coolant is sucked into the cylinder any pressure exerted is relieved by the relief valve. To check this a simple pressure test is easy to do - fix up a schrader valve to the cap and inflate with an air line - then keep checking the pressure.
Sorry to be blunt but if that's what it takes to get the message across so be it.

[Welly]

Oh and fitting a thermostat will not increase the coolant pressure

Without a stat, at this time of year, the coolant will not heat up - especially on a HDi. If the coolant stays cool/warm then it cannot build pressure and whatever the problem is with the car it will most likely stay hidden in this state. If you fit a thermostat you are allowing the coolant to reach full temp (and presssure).

coolant is sucked into the cylinder any pressure exerted is relieved by the relief valve

Coolant can bleed into the cylinders when the engine is off but a cylinder-to-waterway breach in the HG will allow the cooling system to overpressurise (jameslxtd had this on his HDi and posted a big thread about it all) it seems the HDi will not "blow" the relief valve/cap but rather it prefers to pressurise the hoses enough to blow a hose off or take out the water pump.

Not saying this guys HG is gone and I hope it isn't but it does happen.

[Longintooth]

Hi
Any pressure from the cylinder to the water jacket will be discharged through the pressure relief valve and this will prevent any excess pressure caused by exaust gas and remember it is a gas pressure that vents off and this does not vent water away*, but as there is the maintained system pressure, water is forced back through the gasket into the cylinder on the induction stroke hence water loss, if there is a head gasket fault this in itself will not show up a gasket leak but as I said this can be checked easily - gaskets start to leak slowly and pressure leaks will be small at first otherwise the engine will be running extremly rough and water loss severe. That said the reason why the thermostat was removed is obviously someone thought this was the cause of some overheating and is the wrong way to deal with this problem at least as a remedy. Overheating will rarely cause overpressure of a cooling system simply because the system will vent the excess pressure off. As I stated ealier the root cause of overheating apart from low coolant is the inability of the radiator to dissipate the heat often because the core tubes are blocked thus reducing the effective area of the radiator. This hypothesis is easy to replicate if you posses a pressure cooker- no matter how much you turn up the heat the pressure of steam is released and it will not get any hotter - it just boils off faster since there is no radiator on a pressure cooker. Remember a modern vehicle system can go up to 160 degrees C before it boils and the temp gauge would be well off the scale, so as long as there is water in the system no damage would be done. If there is no water sloshing around the cylinder and head the temperature rapidly goes to hundreds of degrees and will cause seizure of pistons, rings and warped heads. Crumbs if the pressure relief valve is faulty it should be rectified immediately since there will be an explosive and dangerous situation and Peugeot should be notified for a recall - only an idiot would take out a thermostat to try and reduce temperature if that was the case. My concern is the repeated assumption that many faults should be regarded as normal for this or that and accepted - wow.
*Many modern systems incorporate an automatic overflow from the filler cap to another smaller tank so has the water expands it spills into it, then when the system cools down it contracts and sucks the water back up. The relief valve is incorporated in that tank so that it does not loose water in the process.
However, this post started out as a Turbo leak problem and hopefully that has been covered.

Food for thought - an opinion can never change a material fact.

[Welly]

I don't work on cars for a living but I was only recalling what happened to james on here and, for whatever reason, his hoses were blowing off under pressure and his head gasket had failed. Our car's cooling system squeezes the air gap above the water line in the expansion tank to maintain a system pressure - sometimes it releaves a bit, holds back, releaves etc and also it will let air back in when cooling down. Maybe they stick or maybe the hose connections become an easy path for the pressure after a few years?

I was thinking that someone had removed the thermostat to at least drop the running temp and pressure a bit and maybe it worked? I agree though that the rad might be partially blocked and was showing high temps on the gauge which would also point to this cheap fix of removing the stat.

[mjb]

The pipe from the top of the intercooler to the maifold - I took it apart today as I was changing my thermostat and firstly no thermostat (a bit worrying!!!)

There won't be a thermostat on the air line. It'll be on the coolant system

[Longintooth]

Hi
Well I got the impression initially that Harrywy was confusing the intercooler to manifold pipe with the coolant pipe and I have attempted to clarify that point. But since he went on to say he was draining the coolant and that he was trying to fix a coolant problem. I guessed that he eventually found the thermostat housing and correctly identified it had no thermostat but he would not find it in the intercooler cicuit as MJB and I correctly points out. This has become two issues one a leaking turbo seal and two a coolant. A point that welton is making is correct that as the temperature rises the water expands and does compress the air that is sitting above the water line in the header tank in any water cooled internal combustion engine. The valve is a pre determined spring pressure acting against the
rising water pressure in a two way valve arrangement so that pressure can be relieved from the system and yet allow air to enter when it cools to prevent a vacuum forming in the system. If this was not the case the hoses would collapse inward every time it cooled and the same would occur with the thin copper tubes
that form the radiator core only they may not expand out again when heated back up, in any case this continual expanding and contracting of the core pipes would fracture them in no time. Personally I have never heard or witnessed a radiator presssure cap or valve failing to relieve pressure on any car or commercial vehcle in my time - it is impossible on paper and it is designed to be fail safe. Hoses and their fittings are designed with an end contour so that when a clip is fitted it is absolutely impossible to blow off - the hose would split apart first with tremendous force or the cores in the radiator would fail first. There is no "if" or "maybe" that is the case. I therefore can't understand how this fellow James incurred this event - was it a broken clip or not tightened securely mmmmm.
The phsyics of the cooling system are simple - prevent boiling ever occuring by increasing the pressure since as soon as water boils (100C at atmospheric 14.5ilb/sqin) it creates steam and that is serious, therefore, the pressure increase is created only by expansion which is an easier devil to manage. By using a thermostat a controlled amount of water/coolant chilled by the radiator is bled in to the circuit but the radiator must be more than capable of cooling the water that is passed - greater than the engine can produce. A bypass circuit is in operation when the engine starts from cold for quick warmup then the thermostat maintains the temperature by fluctuating between the bypass and the main circuit.