Turbo Failure?

About two years ago when I first aquired my 760 turbo, I noticed that there was some oil in the hoses going from the turbo to the intercooler. Now, after driving it somewhat hard, it apears that the turbo has quit. When you try accelerate hard and the turbo trie to kick in, the car stalls out, and there is no posotive reading on the bost gauge. There also appears to be more oil around the turbo, although when I removed the intake hose, the shaft did turn around without problems. Have some of the turbo seals just failed? If so how do recomend removing the manifold bolts. I hear those are very hard to remove after 19 years.

Before condemning your turbo check all the hosing and the intercooler for leaks. The hoses seem to suffer from oil contamination softening them to the point of collapse or splitting, which means that you may be faced for a hefty hose replacement bill and a thorough clean out of the intercooler. IPD have a good stock of silicon hoses for turbo cars. Try them on . All the best, Peter. :car-smiley-031:

After reading this, I had some else attempt to start it with all the hoses disconected while I looked in the turbo with a mirror. The turbo does apear to rotate fine before the engine stalls. What hoses are you talking about? The hose going from the airbox to the turbo has been repalced recently. Also how should I test the intercooler for leaks? Should I run some compresed air through it with an air compresser and block the other end with my hand.

There should be hoses linking the turbo to the intercooler (usually via short cast arms and a further very short hose at each end of the intercooler). The intercooler is then linked to the inlet manifold via the Air Mass Meter. The one from filter box to turbo you say has been recently replaced. If the air filter is in need of changing you should do this as otherwise the engine will be starved of air. All the hoses I have mentioned are capable of failing, as is the convoluted one from AMM to Throttle body. You also have hoses that connect the Idle Air Control Valve into the inlet tract. These, too, can fail starving the engine of air (by letting it leak out). To test the intercooler for leaks block one end and fill with water under slight pressure. It should then be obvious if the intercooler has sprung a leak. All the best, Peter. :car-smiley-031:

Hi, You have replaced the air hose most likely to fail ( air box to turbo). The thing to remember on a turbo is the air pipes from the turbo outlet to the throttle body ( including the intercooler) operates in both vacuum and pressure. This can mean a pipe which looks OK will split and let air out under pressure with the turbo pressure. As the MAF is in the Air Filter, a pipe split will cause car to stop ( usually showing a Engine Lambda light ). If you run engine with ducts disconnected, the same thing will happen. If you wish to run engine to check something with an air pipe disconnected , disconnect MAF plug. You will then have to reset the Lambda light. This can be done by disconnecting the battery ( provided you have radio code ). The intercooler can fail, but if unlikely apart from stone damage. The hose from the turbo to the intercooler is less likely to fail as oil cannot sit in it. Do check the jubilee clips are tight. The air hose most likely to fail due to oil is the short one connecting the intercooler to the metal duct pipe on way to the throttle body. It usually fails at its lower part. You will have to remove pipe to check properly. The elbow pipe can also fail from oil contamination where it connects to the throttle body. Also check the small air pipe from the idle air valve to the manifold as they can split under turbo pressure. What miles are on the engine. Turbos usually fail around 170k miles ( depending on oil changes and owner care ). If oil is leaking from the rear turbo bearing, the intercooler will have oil in it. It can be drained. Check the engine breather box and over engine pipe for blockage. If they are blocked, oil cannot drain from turbo and the oil in the turbo will then leak out into the ducts from the aft bearing. ivor940