Big Dave

Another 928 owner near me (who doesn't have internet access) called me and told me that he's gotten some bad news from the Porsche dealer.

His car was having problems and cutting out on him. He had it towed to the dealership. It is interesting to note that the car did start but died after about a second when the flat-bed truck was there to pick it up.

The dealership did not examine anything electrical. Instead, they drained the oil and are saying that it has a fuel smell to it. Generally, the oil stinks badly, is black and seems burned. The oil was changed about 800 miles ago at a Pennzoil Oil Shop. It's "semi-synethic."

The dealership is saying that the oil has metal in it, and that the crank has seized. They are saying he needs a new engine ($30K) and the labor to install it ($10K). They are guessing that an injector got stuck open, and that gas mixed with the oil, making it seize up the crank. They cannot turn the crank by hand (we haven't tried it yet).

Obviously, this is bad news for the owner (Rob).

The fuel pump was replaced recently, and additional work done to stop leaks back there. To me, the fact that the car started and then died as it was being put on the flat bed sounds like a fuel supply issue....i.e., a dead pump, bad relay, or similar.


1. What would have to happen to cause a crank to seize?
2. Does the dealership sound credible (considering the fact that the car did start before being taken there)?
3. Should Rob re-fill the engine with oil and try to start it again to see if it's actually seized? Any harm in trying?
4. Any other ideas?

Rob obviously is hoping this is a classic case of the dealership getting the diagnosis wrong. I'm hoping the dealer didn't screw up the car more than it already was (causing the seizure).

Thanks in advance.

ErnestSw

Sounds like a crock to me. I wouldn't buy the diagnosis.

Jim V

I'll assume it's auto, could be the dreaded thrust bearing failure.

At $40K for a replacement I'd be looking for a different shop no matter what's wrong with it. That kind of quote has turned many a man into a DIY'er

Gretch

The symptoms sound like hydraulic lock to me. IE an injector has leaked gas into a cylinder and that is why the oil smells like fuel and the crank won't turn. DO NOT attempt to crank engine over. Remove plugs and see if engine can be cranked over by hand. If it can and it spills gas out of a plug hole, you have found the problem. break down the fuel rail and injectors. R&R the injectors. dry out the cylinder(s) replace oil and filter and see what happens.

oh BTW, do not trust the dealer.....................

toofast928

Have the dealer prove that engine is seized. Ask the tech to put the 928 on a lift and watch him bar the engine over. (turn the crank by hand). The dealer's explanation for the crank seizing is credible (lot's of fuel would dilute the engine oil) but, it's rare for bosch injectors to stick, let alone to stick open. Anyway you can test this theory by sending the injectors to a fuel shop for testing.
As for the dealer's cost; I live in NJ. You could have the 928 flat bed to me, I will diagnose and if the engine is seized I'll rebuild it. Then flat bed (or drive) the 928 back to you. $10,000 sound too much?

Big Dave

Keep the comments and questions coming.

I plan on printing this out and taking it to Rob. I'll probably take a trip to the dealer with him and grill the mechanics there about what they're doing.

As for the dealer doing any more work, I agree that their quote has pretty much eliminated any possibility of them continuing to be involved.

If Rob's got the garage space, I'm thinking he ought to have the car taken back to his place so we can diagnose the problem ourselves.

Gretch: hydraulic lock? Where would this be?

Jim: As to the thrust bearing issue, the car was making no noises at all that would suggest metal-to-metal grinding.

Lizard928

Dave, a hydrolic lock is when you have the valves close and the cylinder full of a fluid (gas, water, oil etc.) this then causes a hydrolic lock as these fluids are not compressable so it cannot push the piston up,

Gretch

Thanks Liz..............Yep that is the description. An engine in this condition MUST NOT be turned over as you will surely do damage to the rod bearings and quite possible the crank journal. You MUST remove the fluid from the cylinder first.

Big Dave, I would advise your friend to go get the car immediately. The numbers they are quoting are stupid and insulting. They are taking him for a sucker. Head for the door, fast.

GMS

If the LH control unit failed it is possible for the injectors to be open all the time the ignition is "on". Pulling the spark plugs will reveal if that has happened and if the engine suffered a hydraulic lock.
Obviously, we are only gettting part of the story here, so before condemming the dealer ( and I work at a repair shop) one should get all the facts.

If you can rebuild a '89 928S4 engine properly for $10k, and give a warranty you are doing really well. The dealer's prices are out-of-line, but as most of the official Porsche dealers don't want to work on anything out of factory warranty, that is probably a guestimate rather than fact.

I don't know what the current price for a factory engine is, but the labor charge is definitely wrong. Anyway, why anyone would take any 14 year old car to an official dealer in the first place???

Big Dave

Rob's at the dealer right now....but his phone is turned off. I'll tell him to grab the car ASAP and get it back to his own garage. We'll get it done for 'em.

Lizard928

I do doubt that it is a hydrolic lock though as it wouldn't run and as soon as you tried to crank it you would bend connecting rods.
it is possible to be a TBF though

Gretch

Liz, I am thinking the attempt to turn it over just before loading it on the truck is where the fuel dump took place. TBF it may be, but fuel in the oil is odd for that event.

There is a boat load of knowledge here, with a little bit more information we will know what this shark is ailing from......

Lizard928

gotcha gretch, thanx

Big Dave

I just talked to Rob:

1. The dealership did NOT pull the plugs. They put the car up on a lift and tried to turn the crank by hand. When the mechanic couldn't get it to turn while he was "hanging off" of the wrench under the car, they assumed it's seized.

2. Rob has the oil. It looks black to him (again, approx 800 miles since last change), and he thinks it looks thinner than it should be. He going to pour some of it through a coffee filter to look for metal.

3. He's getting the car flatbedded back to his place.

4. Timing belt was last change at around the 60K point. The car has approx. 81K on it now.


First thing we'll do is pull all of the plugs and try to turn it by hand and watch for any gas trying to escape. Rob has an extra fuel injection brain. He replaced it with a new one since he was having problems some time ago. Assuming nothing else appears to be the problem, and the crank can move after the plugs are out, we'll swap brains to see if it helps.

Rob's got a very nice condition car....it would be great to keep it on the road.

Thanks everyone for the input. If you have more questions or comments, please keep adding them.

I guess my new service covers are going to be put to good use...always happy to help a friend.

Dave

Gretch

Have Rob dump a little bit of the oil on a solid flat surface (outside) away from anything flamable. Touch a match to it to see if it ignites........If it has gasoline in it it will, if it does not immediately ignite, it does not have much, if any gasoline in it.

Remove the breather hoses. take a flashlight and look through the holes in the top of the timing belt covers. you are looking for signs of a schredded timing belt.

Pull plugs, see if you can turn engin over manually, (correct rotation, NOT backwards).

drag magnet through oil or as you suggested, pour oil through a rag, clean old "t" shirt works well. Look for metal bits.

Tell us what you find.