When Diesel Turbos fail, symptoms - Volvo V40 1.9 TDi
Discussion
I know all the symptoms on petrol cars but not familiar with Diesels, infact never even looked at a TD engine before - was a suprise to see the inlet manifold and exhaust manifold on the same , but anyway..
Just been round to a friends to examine his car as it has lost power significantly and he said driving it its as if the turbos stopped doing anything. My first thought was a blown off intercooler pipe.
It starts and runs fine and absolutely no smoke out the rear, but it appears to have been leaking oil from where the intercooler pipe to manifold meets, as all the back of the engine is oily where it looks to have been dripping/ seeping for months. All pipes appear to be connected up fine and reving the engine you can hear the turbo spin up but it does very quickly decelerate. Whipped the turbo inlet pipe off and it wasn't significantly oily, no more than expected from the crank breather, the compressor wheel spins freely and doesn't have any play in any direction and no obvious damage.
So the turbo appears knackered whatever with the sudden deceleration and it did need quite a stamp on the throttle to get it spinning, damaged exhaust turbine? But that doesn't explain the oily intercooler pipes if the oil seals had gone and bearings damaged how come no play and no smoke out the exhaust? Do the Diesel filter things work well enough so clean the exhaust fumes up to completely smokeless?
Could the exhaust turbine suddenly have fallen apart and the weeping bearing are unrelated to its sudden demise?
Just been round to a friends to examine his car as it has lost power significantly and he said driving it its as if the turbos stopped doing anything. My first thought was a blown off intercooler pipe.
It starts and runs fine and absolutely no smoke out the rear, but it appears to have been leaking oil from where the intercooler pipe to manifold meets, as all the back of the engine is oily where it looks to have been dripping/ seeping for months. All pipes appear to be connected up fine and reving the engine you can hear the turbo spin up but it does very quickly decelerate. Whipped the turbo inlet pipe off and it wasn't significantly oily, no more than expected from the crank breather, the compressor wheel spins freely and doesn't have any play in any direction and no obvious damage.
So the turbo appears knackered whatever with the sudden deceleration and it did need quite a stamp on the throttle to get it spinning, damaged exhaust turbine? But that doesn't explain the oily intercooler pipes if the oil seals had gone and bearings damaged how come no play and no smoke out the exhaust? Do the Diesel filter things work well enough so clean the exhaust fumes up to completely smokeless?
Could the exhaust turbine suddenly have fallen apart and the weeping bearing are unrelated to its sudden demise?
Breather pipes can mess up the turbo when all furred up.
As for the differences in failures, well, wow, there is a huge important point...
Diesels don't have throttle plates, they suck in as much air as they can, and add whatever fuel they need. Control of the power is done by controlling fuel injection. A petrol car controls the amount of air going in, and just meters the fuel to keep it from going too rich or lean.
Now... as a diesel fires from compression, and doesn't need a spark, and controls power by fuel quantity, when a turbo seal goes, it can blow the engine oil into the engine, burn that, and runaway, fueling itself and switching off won't stop it!
http://www.youtube.com/watch?v=5zx3qKX_Pno
just like that...
As for the differences in failures, well, wow, there is a huge important point...
Diesels don't have throttle plates, they suck in as much air as they can, and add whatever fuel they need. Control of the power is done by controlling fuel injection. A petrol car controls the amount of air going in, and just meters the fuel to keep it from going too rich or lean.
Now... as a diesel fires from compression, and doesn't need a spark, and controls power by fuel quantity, when a turbo seal goes, it can blow the engine oil into the engine, burn that, and runaway, fueling itself and switching off won't stop it!
http://www.youtube.com/watch?v=5zx3qKX_Pno
just like that...
Diesel is very similar to oil. The compression of a diesel engine is enough to combust oil so there won't be any blue smoke like there would in a petrol.
Most older turbo diesels will burn a little oil and finding traces of oil in the intercooler is not uncommon, although puddles of it are a bad sign.
Another fairly common symptom of turbo'd engines is the induction pipe work before the turbo getting weak and pinching up as the turbo tries to draw in air. This causes the engine to cut out as the turbo starts to wind up.
Most older turbo diesels will burn a little oil and finding traces of oil in the intercooler is not uncommon, although puddles of it are a bad sign.
Another fairly common symptom of turbo'd engines is the induction pipe work before the turbo getting weak and pinching up as the turbo tries to draw in air. This causes the engine to cut out as the turbo starts to wind up.
Ah, so fully combusting the leaked oil does away with any smoke as you'd find in a petrol car, that makes sense. I guess it must have a damaged exhaust turbine and weeping but not totally shot seals, the damaged exhaust turbine causing the reluctance to spool.
I've told him to phone Owen Developments who are the Garrett main dealer and conviently local to enqire as to a replacement or refubishment and to fit it himself. Access actually looked suprisingly good, he spanners his MGB Roadster himself but has always avoided modern car maintainance out of lack of interest, sure he's perfectly capable. He phoned one local back street garage to be told, air sucking through teeth, an "absolute minimum of a grand mate" so I'm sure that price for a fix can be easily beaten.
I've told him to phone Owen Developments who are the Garrett main dealer and conviently local to enqire as to a replacement or refubishment and to fit it himself. Access actually looked suprisingly good, he spanners his MGB Roadster himself but has always avoided modern car maintainance out of lack of interest, sure he's perfectly capable. He phoned one local back street garage to be told, air sucking through teeth, an "absolute minimum of a grand mate" so I'm sure that price for a fix can be easily beaten.
Found a mobile turbo chap who will do a reconditioned turbo including fitting and year warantee for £650. Sounds a good deal and he's doing it tomorrow. For comparison volvo wanted £850+vat +fitting. A new turbo off the shelf from garrett dealer was £550+vat. Proof is in the pudding as such so will report tomorrow on the service.
Herman Toothrot said:
duncancallum said:
Are you sure its not the airflow meter. its a common fault on turbo diesels
Would that have an effect on off boost running? It runs, idles etc fine.The MAF went on my 330d a few years back. Idled and drove fine low down, but above 2500 revs there was nothing.
its normaly what happens to them there a "hot" wire sensor.
After a period of time the hot wire gets coated in crap and the thing goes out of callibration and you get no fuel on boost.
you can tell when my MG ones starting as its has a huge dead spot when you try to pull away and then once the sensor wakes up it boosts like a good'un
After a period of time the hot wire gets coated in crap and the thing goes out of callibration and you get no fuel on boost.
you can tell when my MG ones starting as its has a huge dead spot when you try to pull away and then once the sensor wakes up it boosts like a good'un
Aah another MG weasel owner. Yes the MAF sensors can make a big difference for the low down grunt on them, and I think a worn MAF might have some effect at the top end on the 111bhp mapped cars (ZR115, ZS115 etc.). I have found that using electrical contact cleaner or brake cleaner on the MAF has always pepped it up for me, mine is ion the original MAF at 80,000 miles now. Currently I don't have the MAFAM fitted, just clean the MAF once a year or so, so I don't need to go through any potential hassle with the insurance company. Also I just service the car today, and bar rear brake pads and a wiper blade, it's in very good health.
Anyhow, back on topic... In the case of the Volvo, I would be pursuing the turbo being stiff to turn, although I've never touched the inside of one so wouldn't know whether it was normal or not.
Anyhow, back on topic... In the case of the Volvo, I would be pursuing the turbo being stiff to turn, although I've never touched the inside of one so wouldn't know whether it was normal or not.
pilchardthecat said:
Herman Toothrot said:
duncancallum said:
Are you sure its not the airflow meter. its a common fault on turbo diesels
Would that have an effect on off boost running? It runs, idles etc fine.The MAF went on my 330d a few years back. Idled and drove fine low down, but above 2500 revs there was nothing.
t955daytona said:
pilchardthecat said:
Herman Toothrot said:
duncancallum said:
Are you sure its not the airflow meter. its a common fault on turbo diesels
Would that have an effect on off boost running? It runs, idles etc fine.The MAF went on my 330d a few years back. Idled and drove fine low down, but above 2500 revs there was nothing.
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