944 Turbo S Engine Rebuild Thread
- Thread starter Eldavo
- Start date
Brilliant! Did you make your trigger sensor bracket?
I've remade mine a couple of times because I thought the alignment was causing occasional kickbacks during starting, enough to have snapped the nose off the starter recently. Also below freezing starts were difficult at best, it was fine once running.
Turns out I had the VR sensor too close for years.
Face palm moment
I've remade mine a couple of times because I thought the alignment was causing occasional kickbacks during starting, enough to have snapped the nose off the starter recently. Also below freezing starts were difficult at best, it was fine once running.
Turns out I had the VR sensor too close for years.
Face palm moment
PSH
PCGB Member
haha.. could be... I'm expecting another moan from my MOT station this year, last year he moaned that I had done less than 2k miles since the previous ticket... I reckon this year will only be 1k miles.... the engine is still under 20k miles since rebuild...lolblade7 said:Mine only gets used on my favorite back roads, I reckon it spends more time on boost than yours Pete [PSH said:].
James0 said:
Nope - I bought the GSF trigger wheel and a bracket they do that mounts on the aircon tensioner. Gapping it to 0.8mm is far easier when you can just slide a feeler gauge in with loads of space!
Popped along to the garage today, they’d just fitted the new Bowden cable for the boot release, reseated a hose that was weeping slightly and we ran it up to temperature and ran the Auto-Tune feature for the cells from idle up to 4K rpm and low boost after setting the overboost protection at 18.5psi. Changing the plugs on Monday and then bringing it home.
Slightly painful update.
Engine is back out of the car and in many pieces again. Did circa 250 miles and used 2 litres of oil. Borescoped it myself and the bores were badly scored, fuel in the oil, tons of oil blow b, plugs fouled, etc. Removed the head and stripped all the accessible bits off the engine during lockdown and then dropped it in the garage for them to drop the engine. Took 8 hours to get the engine out and stripped the rest of the way down - easy second time around []
Pistons are beyond knackered - they’ve shed the coating and it was stuck to the oil strainer in sheets/flakes. Bores are eaten alive and only a sleeving job will save the block. Block and pistons are with the machine shop for them to speak to Wössne but I’ve been in touch with an Australian shop just outside Sydney who have confirmed that after 10 years of 20-30 Wössner Piston/Alusil rebuilds they’ve had the last 2 fail in the same way due to a change in the piston coating.
Looking at Westwood iron dry liners with Wössner pistons again, worst case scenario I can have a viable sleeved block and piston setup for £1500-£2k within a matter of weeks but I’ll prepared to wait a bit longer and see what the outcome is from Wössner first. I have a spare block too, so if this drags on then I can just get that one done in the meantime.
Will update when there’s something to update.
Engine is back out of the car and in many pieces again. Did circa 250 miles and used 2 litres of oil. Borescoped it myself and the bores were badly scored, fuel in the oil, tons of oil blow b, plugs fouled, etc. Removed the head and stripped all the accessible bits off the engine during lockdown and then dropped it in the garage for them to drop the engine. Took 8 hours to get the engine out and stripped the rest of the way down - easy second time around [
]Pistons are beyond knackered - they’ve shed the coating and it was stuck to the oil strainer in sheets/flakes. Bores are eaten alive and only a sleeving job will save the block. Block and pistons are with the machine shop for them to speak to Wössne but I’ve been in touch with an Australian shop just outside Sydney who have confirmed that after 10 years of 20-30 Wössner Piston/Alusil rebuilds they’ve had the last 2 fail in the same way due to a change in the piston coating.
Looking at Westwood iron dry liners with Wössner pistons again, worst case scenario I can have a viable sleeved block and piston setup for £1500-£2k within a matter of weeks but I’ll prepared to wait a bit longer and see what the outcome is from Wössner first. I have a spare block too, so if this drags on then I can just get that one done in the meantime.
Will update when there’s something to update.
Wössner accepted responsibility with the Australian shop and replaced the pistons. You can bet your bottom dollar there’s a line in their T’c and C’s that limits their liability to their product only though!
Will see what happens, it wouldn’t cost me anything to take a legal route (Dad’s a partner in a large firm) but for the relatively small costs in dispute vs the time expenditure I don’t plan on going down that route unless I’m properly pushed.
Will see what happens, it wouldn’t cost me anything to take a legal route (Dad’s a partner in a large firm) but for the relatively small costs in dispute vs the time expenditure I don’t plan on going down that route unless I’m properly pushed.
Dan944t
New member
really sorry to hear this! ??
if you do go the westwood iron linners route, that’s what i’ve got made and fitted , but i personally wouldn’t go with the wossner pistons again? i’d try and get the money from them ?? and change pistons. im running a racing piston and rings with my iron cylinders from an argentinian racing firm thats been around many years , and was told it was a good match for them. ( same pistons and rings as Pete uses on his standard cylinders) the name escapes me......just remembered IASA and i got bespoke one off conrods made in Milan who make for other porsche models but i’m the first 951. super light. i assume yours will be fine just the bearing area will need inspecting.
shity news mate ??
mines still got the head off as i’m making a home head preasure tester as i’m assuming i have a hairline crack somewhere? 3rd time lucky ??
hope you get compensation out of them, i personally wouldn’t go back with there pistons mate. i was told by John at Serdi that all these are made in china and poor materials used ? that’s why he told me not to go for them anymore so he told me about the IASA piston and rings, there slightly thinner rings too.
if you do go the westwood iron linners route, that’s what i’ve got made and fitted , but i personally wouldn’t go with the wossner pistons again? i’d try and get the money from them ?? and change pistons. im running a racing piston and rings with my iron cylinders from an argentinian racing firm thats been around many years , and was told it was a good match for them. ( same pistons and rings as Pete uses on his standard cylinders) the name escapes me......just remembered IASA and i got bespoke one off conrods made in Milan who make for other porsche models but i’m the first 951. super light. i assume yours will be fine just the bearing area will need inspecting.
shity news mate ??
mines still got the head off as i’m making a home head preasure tester as i’m assuming i have a hairline crack somewhere? 3rd time lucky ??
hope you get compensation out of them, i personally wouldn’t go back with there pistons mate. i was told by John at Serdi that all these are made in china and poor materials used ? that’s why he told me not to go for them anymore so he told me about the IASA piston and rings, there slightly thinner rings too.
Will see what happens, given that even Buchanan have done 20-30 rebuilds with Wössners before this and are still using them but in iron bores it speaks for the quality of the piston itself - coating aside.
Even my machine shop said that Wössner is their go-to brand because they are so consistent. They don’t even bother measuring them anymore as their QC is spot on and every piston is dimensionally accurate - I’m assuming the coating is farmed out then!
If Wössner just effect a replacement set of pistons then I’d be daft not to just use them and crack on. Despite guzzling oil and eating it’s own bores the engine was intoxicatingly sprightly and I don’t want a long protracted wait until I can use the car again - again!
Even my machine shop said that Wössner is their go-to brand because they are so consistent. They don’t even bother measuring them anymore as their QC is spot on and every piston is dimensionally accurate - I’m assuming the coating is farmed out then!
If Wössner just effect a replacement set of pistons then I’d be daft not to just use them and crack on. Despite guzzling oil and eating it’s own bores the engine was intoxicatingly sprightly and I don’t want a long protracted wait until I can use the car again - again!
blade7
Well-known member
Eldavo said:
There's been issues with Alusil coatings on JE and Mahle aftermarket 944 pistons for a while. It seems odd the OE's can turn out 100's of 1000's of these engines today, but it the repair market struggles. I've had everything but the pistons to build a Alusil 3.0 for years, but whenever I got motivated to do it, research threw up new unresolved issues/pictures like yours.
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