Diagnosis please!?

[DrOzLov]

Hi Navarians

I have a D40 Spanish 2007 2.5 lt diesel.

Attached are the photos of oil leaking/being sprayed on my air hoses and bonnet. Can someone please give me a diagnosis of the problem? It is definitely a problem as the air intake manifold should not be spraying oil on the fan housing!

Btw. the car runs good, I am just concerned and keen to prevent any serious damange.

Thanks

Dr. OzLov

 

[Old.Tony]

There are two things happening here (one is expected, the other not).

First, oil is being vaporised in the crankcase and is passing up through the PCV. In the second photo, it's the hose just to the right of dead centre of the photo, partly wrapped in ribbed aluminium. This hose goes from the top of the camshaft cover to the air intake just before the turbocharger. Oil and exhaust gas (the result of blow-by) are drawn out of the engine into the suction side of the turbocharger, pumped through into the pressure side. This is a normal and expected operation. The oil is passed into the intake manifold (where it unfortunately combines with EGR soot and forms a black gunk) and is then combusted by the engine.

The amount of blowby (and oil vapour) increases with age as the cylinder bores and piston rings wear. This can be reduced by fitting a catch can in that PCV hose. Catch cans provide place for the oil to condense and must be emptied on a regular basis (either back into the sump, which is acceptable, or disposed of appropriately).

Second - the hoses on the high pressure side of the turbocharger (anything between the turbocharger and the intake manifold) are aging and have split and/or have come loose. Although typical boost levels in a D40 rarely exceed 20psi (and atmospheric pressure is 14.7psi), it's still enough to force air out of the joins/cracks.

If you remove the clamps around the affected area you'll be able to examine the hoses. Flexing them should reveal cracks and splits. Silicone hose replacements are good, be careful about adding too much hard pipe (if you decide to go that way) because the hoses are there to allow the engine to move (the intercooler doesn't move).

While you're replacing hoses, you might want to pop that intercooler out and clean it. I used ordinary unleaded fuel in mine, poured about 100ml in and let it run back and forth while I turned the intercooler to let the fuel pass through as many of the cores as possible. On the fifth rinse the fuel started coming out reddish again. The intercooler comes out the front, pop the grille out, remove the two bolts at the top of the intercooler and the two hose clamps (the one on the right hand side of the vehicle is a bugger to get to).

 

[DrOzLov]

Any thoughts on turbo?

Thanks Tony, you are a legend!


1. I have planned to install a catch can this weekend. Am aware of blow by

2. Was not aware of potential hose issue. Will definitely examine it and will certainly try clean the intercooler.

To be honest, I was told by a few guys that the issue I have was result of my turbo ageing and that I should slowly start thinking about a turbo recon. What are your thoughts on this one?

Cheers

Dr. OzLov

 

[Old.Tony]

Turbochargers do get old, I just had mine replaced - and I have a fair idea on how to look after it! The mechanic who pulled it out said it was probably a bit early to replace it, it might have lasted a bit longer, but I pointed out that we work it hard when towing and we love to travel a fair bit - and we don't want to have the turbo blow up while we're cruising up the Silver City Highway.

However, turbochargers rarely spit oil externally like that when they're aging. It's usually the (brass) journal bearings (which is what the Garrett 2056V uses) that wear first, and sometimes cause minor wear on the turbo main shaft. If the bearings wear enough, the impeller may be able to contact the housing and that's where the excitement begins (and you could read that as "towing" rather than excitement).

Inspection before ordering any bearing kit is vital, because just replacing the bearings might not be enough. We saved ourselves time - ordered a Forefront Industries turbocharger (Jamie is not only knowledgeable but he ships really fast).

With all that said though, the pictures provided look more like a boost leak than a turbocharger failure.

 

[DrOzLov]

Cheers chief...and boost leak is what you described initially? Or something else?

 

[Old.Tony]

Yep, a boost leak is any leak of pressurised air between the turbocharger and the intake manifold.

 

[longy509]

This has just happened to me a couple months back and a few weeks back. photo 1 i rekn your hose is split underneath or at least that is what happened to mine and i bet you are blowing a shit load of black smoke and lacking power when the engine is hot im assuming the split only opens when hot i replaced it with a forefront industries hot pipe oil spray gone and more power just make sure you use the correct size hose clamp as mine popped off and hit the bonnet putting a dent in it and popping the paint off.


Photo 3 i just replace yesterday with a forefront industries cold side pipe as i had notice oil drippling out probably could of got away with just tightening it but figured its aging anyway.

 

[DrOzLov]

Many thanks guys! This helps immensely! I reckon you are right, the pipes might be gone. Will definitely check it tomorrow.

 

[DrOzLov]

Ok, so did the intercooler clean today. Also took off hot and cold pipes and could only identify cracks/cuts in hot pipe, but not in cold pile. Cold one actually spits/leaks more oil than hot one.

When I cleaned the intercooler (following Old.Tony's advise) the unleaded petrol came out black as.

Oil catch can installed but not connected. Got me self wrong hoses...too small, need a size up. Scheduled for next weekend.

Anyway, after I've done all that, the idle was much smoother and more consistent than before. So thumbs up! Cheers guys.

I need to upgrade the hot pipe. Thinking of getting a steel one, BUT concerned that it might stuff up the engine....my understanding is that the steel one does not expend at high revs and hence pushes more air into the engine...so I am thinking, this might put more strain on it and stuff up something....it is an older model, 2007 with 233000k...I am the second owner....looking for advice!

Cheers

Dr. OzLov

 

[Old.Tony]

Hose expansion increases lag. Solid piping reduces lag - the pressure going into the engine won't cause it any drama, it's well below what the engine can tolerate anyway.

 

[DrOzLov]

Thanks man! Much appreciated.