Porsche Enthusiasts Club Forum

hi all

i need your help, last night i stop the car got out picked up my girlfriend then went to start it again but it did not start and tirned over too fast, cam belts gone!!!!!!!
just took it to bits and yes it is missing some of its teeth,is that it is the engine scrap???
do the pistons hit the valves??
by the way my car is a 1984 2.5l

thanks for your help

Prepare yourself, this will not be good reading for you.

The 944 is an interference engine (ie when not timed properly the pistons and valves meet). You may have been lucky and not done too much damage as it sounds like you were at low revs but you are going to have to get the head off to see. You are likely to have bent a couple of valves. Once the head is off you can then assess whether to re-build the one you have or look for an alternative one. When you re-build it think about changing the water pump too, a bit expensive but if it goes just after the belts are on then you have to remove the belts again to change it.

Sorry to hear of your bad luck. It is one we all dread.

Very bad luck

However, the fact that it went whilst trying to start may be very fortunate and the damage may be minimal (if any), but you won't know for sure until the head is off. How old were the belts?

are they simple enough to fit (thinking about doing mine, only just got the car and don't want this going)

where is the best place to get them from, i have been told to avoid pattern ones, as they may stretch more than origional

and I know i need to tension it up

Fiddly to fit,I've done loads of cambelts over the years but bottled it with the 944.
No such thing as pattern ones they'll all be Gates or similar. Try Bert at Berlyn Services or German & Swedish. The timing belt is cheapish it's the balance shaft belt that's more money. Check the tensioners carefully & also the oil seals, a common reason for belts failing is oil leaks from the cam, crank or balance shafts degrading the belts.

Do a google for 944 cambelt, I believe their is an article on either Clarke Garages or Pelican.

The engines not scrap, hopefully at worst you bent a couple of valves.
I bought recently a spare cylinder head for my 2.7 complete with valves for £60 on fleabay for just such a calamity.
depends on how good you are with spanners. Its not a bad job.

Re belt change: Recently done mine on my turbo for the first time... It's a fiddly job but by no means beyond the skills of a competent DIYer. The issue you need to come to terms with is whether to tension by feel (90 deg turn on longest travel) or to tension properly with 'a' or 'the' tensioning tool. I went for the latter 'cos I'm a control freak and I couldn't stand the uncertainty of not being sure if it was 'just right'! However, there are lots who'll argue the opposite.

Paul

Do you use this one http://arnnworx.com/new_tensioning_tool.htm, or this one

cheers

You've done your research!! Following some advice from some US 944 mates, I went for the former due to price and the fact that it seems to be quite well regarded... having said that, my indie swears by the 'twist' test.

That looks the value option, the latter if you were a pro doing them regular. Did you have to change any of the front seals ? or the water pump.Mine needs the front crankseal, ive got the set so will do them all incl a new oil pump drive gear and the top-hats have'nt got the tensioning tool (shame you not closer i'd of hired it off you) Looks like a twist and hope option. i've spoke to guy's on here and if you play the game and keep any eye on the method then its case of check and check again till its correct before you go for a start.

what do think?

cheers

The Arnnworx one works fine, as far as I can see. I changed all the front seals, and the top hats for one of the balance shafts and for the cam, and the water pump. The tensioning pulley had been done quite recently so I left that. All seems fine - gave it quite a caning over this weekend and everything's normal. Of course, it will require re-tensioning at the 1000 mile point.

Regarding the tool, my parents happen to live 15 mile North of Bedford. Depending on when you were doing your car, I might be visiting them and you could borrow it... all about timing though

That would be a great help, i work in Wellingborough ...I'm sorting out a date this week to do it will pm you some details if that's ok.

cheers

You have my sympathy ..the worst nightmare.

Anyway I have a late 2.7 (89) and I have read somewhere..I can dig it out if required...that cam belt is self adjusting..? does that sound right ? Not sure haynes has anything to add. My belts have been changed (not by me) but I am keen to know they are adjusted correctly.

The spring tensioner does indeed apply tension to the cam belt automatically, however the manual says that you then have to tweak the tension to get the right level. In my (limited) experience, the tensioner on my engine did not apply sufficient tension. The balance belt is not tensioned automatically so needs setting up manually.

Sorry to bring this thread up again but I've been doing a bit of reading into cambelt replacements in preparation for getting my hands on my 944.

I've never done a cambelt before but willing to learn. Thing is this seems to be one of the more complicated ones and I really don't want to kill my engine. My other problem is there aren't any garages anywhere near me that are likely to have ever seen a 944 before so they can hardly call themselves specialists.

Would you recommend me giving it a shot or just getting it trailered to a relatively nearby specialist?