rawky

I think the water pump died today, is this a common fault? How long would it take a porsche engineer to replace one on a 1991 S4?

Your stories are welcome...

Cheers
Simon

Lizard928

You should explain as to why you think it died. Car overheating? Leaking coolant out of front of engine? Lots of noise from timing belt cover?

I don't know what book time is but I would guess 10-12 hours. Any good wrench can do it in 8 or less (replacing all seals etc.)

rawky

Well,
toothed belt warning came on, then temp went through the roof. There was a ticking sound from the engine and I could see water boiling at the front of the engine.
Recovery man also suspected water pump. Going into specialist today.

Tails

If water pump has failed and as stated the TB warning light came on, the water pump failure possibly caused the TB to go slack.

Do you know whether the WP is a Porsche pump, a rebuilt pump or a foreign cheap import pump.

Was the water pump renewed at the last TB replacement?

Any way if it is the water pump, in addition to its renewal I would suggest the replacement of the TB as well as an overhaul of the TB tensioner and the replacement of the idler roller and pin. Also have the technician check the condition of the TB guide rollers located just under the crankshaft TB tooth driver gear.

In other a total TB overhaul which includes wear to the camshaft TB driven gears.

Tails 1990 928 S4 Auto

rawky

Its just gone a trailer to the specialist, he said that he was going to replace the TB when he changes the water pump....

WallyP

Make certain that he also refurbishes (not replaces) the tensioner. That is a critical part of the process.

Garth S

When the front covers are pulled off the engine, rotate the crank by hand to assure that the timing marks line up prior to further dissassembly ..... it would be comforting to know that that "ticking' noise was not due to valves touching pistons.
I had a similar WP failure on a S4 - the WP bearing cage failed allowing the belt driven pulley to twist and release belt tension ..... and stop rotation by jamming solid against the pump housing = tension alarm and boil over .
If you shutdown quickly enough, everything will be OK.

rawky

The engine had stopped 30 seconds after the toothed belt warning came on..

Jim bailey - 928 International

Ah...."The engine had stopped 30 seconds after the toothed belt warning came on.." I was hoping that YOU had turned off the engine !

rawky

Sorry, My fault, I stopped it after 30 seconds. I think I was quite lucky tbh

Jim bailey - 928 International

OK that SHOULD be good !! Be sure that NOONE try to restart it becauser the belt can vulcanize to the water pump pulley and THEN on an attempt to restart it breaks the belt.... That happened to My Son In Law !!! but it was a 16 valve engine no valve damage....

UKKid35

Simon, I seriously urge you to read up on the cam belt change procedure (Wally's write up is great). You need to be in a knowledgeable position to understand and query your specialist's quote. You need to understand what parts might be worn out and need replacing, and which can be refurbished.

Be aware that the price you will be charged for parts from Porsche will have a significant premium over parts you could source yourself (from one of this site's sponsors).

Also, I do not remember hearing a recommendation for a specialist in the North East, and entrusting your car to an OPC would be like writing a blank cheque. So make sure your specialist has 928 experience, you don't want to be paying for someone to learn on your car. A good question to ask would be - what belt tension tool will you be using? If they can't answer you need to take your car elsewhere.

jon928se

I've heard of a speciailist in the North East - Tom ???? - no recommendations but I've never heard anything bad.

rawky

i used him alot with my 944, and word on the street is that hes a bit of a 928 specialist.....