Porsche Enthusiasts Club Forum

I've had conflicting advice here (mainly from Mr Google!!)
So from other thread, my early 944 appears to have dropped rings on the rear cylinder, its the only one with low compression, the plug is fouled and theere are no stuck valves in the newly rebuilt and reinstalled head. Ive looked at the process for removing engine and that seems a bit OTT for this job (particularly as whole top end has just been put back together - as well as the plethora of wires/injectors etc to get confused with).

I have seen a couple of posts that say its possible to do from underneath by supporting engine from above removing crossmember and a few other bits so the sump can be removed - good U Tube video of this part re replacing crank/rod bearings. What it doesn't show is if there is enough room around Crank to remove the rod and piston complete to allow rings to be replaced. If it is possible then yes we'll do all 4 rings and rod bearings.
Anyone done this, got a definitive answer? I can do some of the disassembly/reassembly myself to save money - if it is possible it could be the difference between fixing and just selling on as is..........
Thanks
Ian

Hi

I haven't tried myself but have seen others say they have done this with the engine in the car. However, you seem to be asking if you can do this with the crank in situ?..if so no...my apologies if I have misread what you have written. On a personal note, I wouldn't do this job with the engine in the car, it's just not the way to do a proper job even if it is physically possible, cleanliness is godliness when it comes to engine rebuilds which IMHO is not possible when trying to do this from under a dirty car. There's also the point that you don't yet know what the extent of the damage is? Speaking as one who has rebuilt one of these engines, take it out, take your time and don't cut any corners, you'll then have a good engine that will most probably out live your time with the car.

Good luck

Pete

Thanks Pete
I thought as much re Crank, shame it happened just after rest of engine was done - at least there would be overlap in labour costs. It was so odd when it happened, no signs other than car lost power and ran lumpy - I honestly thought it it was a fuelling issue or even a dodgy HT lead at first, maybe i'm an optimist.
I watched the engine out Vid on YouTube yesterday, im happy to undo lots of bolts and disconnect bits, its just the amount of electrical bits and other stuff that scared me. Need big rethink on car as I really dont want to spend another lump of money on it - as I thought it was all sorted before and had already spent more than hoped.
Ive advertised it as a project with 'offers invited' as I suspect parts/labour will be prohibitive for me - my fault, got on so well with simple cars like MGBs (head and block off in a couple of hours!)etc, didnt do enough research on 944s.
Ian

If I was you before condemning the rings I would take the head off again and take a good look at the valves and seats, it does seem strange that this has occurred after a head rebuild, is it just a coincidence? has the refreshed head caused more compression (as it should) resulting in a ring letting go or was the work done on the head not as good as it should have been? were the spring rates checked and refitted to Porsche spec? Lot's of variables in there, remove the head first (much less work) and be sure that it's not the cause before doing the much bigger task of removing the block.
At least that's what I would do, these blocks are nye bullet proof if regularly serviced...you don't say which cylinder, if no. 4 ( the one that fails the most due to coolant air lock problems)and certainly if a turbo I would be looking at a burnt valve(engine would be lumpy)....having no experience with the N/A engines I'm not sure if this is likely, could be if for some reason the AFR was way out?

cheers

Pete

Thanks
It is definitely a ring, compression low and engine stalls when oil filler cap removed.
Head will be 're checked when off.it is the rearmost cylinder by the way, no water or coolant ingress anywhere
Car jacked up safely - start removal process soon, feeling quite confident I can remove engine safely - even got a checklist of steps.
Ian

Well, good luck...yes the rear most cylinder is No.4....best to take the engine out from under the car.....it can be done from above but space is very tight and may cause more problems than it's worth...

cheers

Pete

Buy a £30 label printer and label everything before you strip it down, then take photos at each stage. Will save a lot of heart ache when you come to reassemble, especially if a bit of time goes by in between. Make sure all the timing marks are lined up before you start as well, including the one on the flywheel, although this might not be so relevant if the block is coming apart.

Honestly, after the amount of effort and money you have put into the car you should stick with it. You will get it sorted, and when you do it will be a treat to drive. The best way to get pay back is to drive the thing as you intended and let it put a grin on your face Leave the paint job for another year or so. Get it running and driving and get it out on track.

I'm not sure what you mean by dropped rings, but it doesn't take much to damage the Alusil bores so I'd be surprised if the rings were your biggest issue.

Thanks, and others have pointed this out. The engine out and head off will be relatively low/no cost processes, once we can see whats what then I can decide how to proceed......hoping bore is OK.

I almost bought a Alfa before this, fully rebuilt 1.5Ti engine off the shelf for £1250, shame the same isnt available for that price on the 944

Ian

Forgot to take label printer down to garage so have used clearly marked masking tape on the bits that have been removed thus far. Mechanic had already taken some bits off so not sure timing marks are relevant but i'll check.

I have to say, as an ugly duckling in the looks department, it was a hoot whilst it was working, I've just got to convince myself that it wont let me down again...................I need to keep the faith!

Off to Goodwood this weekend so no further work on it after tonight for a few days.

Ian

Enjoy the R&R

All running fine now (head/valve repaired), so decided to ensure cooling system had no air locks......undid bleed bolt, all fine, went to close it and the head came off the bleed bolt - nice blue fountain for a moment or two!
Still at least the engine and under bonnet is a bit cleaner now!
Getting my bolt remover out this evening (carefully) and replacing with a temporary bolt until I can get another proper one - they seem to be available from US only on ebay!

Ian

Why eBay, just go to your Porsche dealership parts department

Inherent fear of Main dealer prices?

Albeit you are second person to tell me that, apparently under a tenner posted so ordering today!

Thanks

Ian

just checked PET

the bleed bolt in the top of the housing on a 1983 944, 931 106 156 00 £3.68 inc vat

and I have updated the prices in my pet system today, so its bang up to date