Head gasket
- Thread starter bradster
- Start date
Hi Pete I purchest the car drive it home 20 miles with no problems ,let it tick over on drive about 10 mins then header tank like a volcano switched engine off so I thought head gasket but looks like mite be the rad .i put new thermo in and still did the same, thing is I flushed the rad out and it seemed to be ok
Bradster
Bradster
pauljmcnulty
Active member
It could well be an airlock. The 944s are very hard to bleed properly, mine did exactly the same.
944 man
Active member
Perhaps its had a leak, or simply new coolant recently? The cars are very difficult to fill with coolant so its possible that the overheating incident was caused by an airlock.
I cant really help further than this, as youre with the car, but the best advice will be very carefully measure the quantity of coolant that you pour into the car. If you dont get 7,800ml in then theres going to be an airlock and itll overheat agin.
Simon
I cant really help further than this, as youre with the car, but the best advice will be very carefully measure the quantity of coolant that you pour into the car. If you dont get 7,800ml in then theres going to be an airlock and itll overheat agin.
Simon
PSH
PCGB Member
Going by what you've checked so far I'd be inclined to think its the rad switch or the wiring to it. Did the fans come on at full power when the engine started to get hot? ,if not the header tank would blow as you described. Over my 14 years of ownership I've had the header tank do this twice and both occasions were due to the rad switch and it's corroded wiring. Last time my son ( top mechanic) re-wired the switch as the wiring had become to brittle to use again, in fact my entire engine loom now has new higher spec wiring+heat shielding thanks to my son...
If the fan runs at slow speed only then it's likely to be the switch , if it's not running at all then check the wiring, usually fails close to the switch itself.
Pete
If the fan runs at slow speed only then it's likely to be the switch , if it's not running at all then check the wiring, usually fails close to the switch itself.Pete
I hope this striping down isn't all because of air lock and money,the fan did come on when reached temp but one speed , think replace rad/switch check thermo and wiring any way.
I've got the engine out of car do you think it's worth replacing shell and piston rings,I didn't check compression but it pulled well ,it's got abit of end float in crank piston are firm in the bore and bores look ok it done 160 miles
Bradster
I've got the engine out of car do you think it's worth replacing shell and piston rings,I didn't check compression but it pulled well ,it's got abit of end float in crank piston are firm in the bore and bores look ok it done 160 miles
Bradster
PSH
PCGB Member
Wow.... Engine out and stripped due to blowing header tank?... No messing going on with you sir....
160k miles on these cars is very little if well serviced, in fact little more than run in. In the 80's a road test was done over a year where the milelage covered was 350k miles, car was completed stripped after and tolerences measured all of which showed very little if any change from unused spec. During this time the car only had servicing according to Porsches handbook, IIRC they didn't even need to replace the clutch. The headline at the time was something like " going to the moon and good as new".
It's difficult to advise about fitting new rings and shells, more so since you have no compression test results to go by. I know you say it pulls well but is that comparing it to other non Porsche cars or 944's themselves.
I guess it's down to personal choice and cost, shells for these cars are not cheap, from Porsche mains and rods are going to be around £800+, half this for aftermarket. If cost is an issue and everything is within tolerance perhaps best leave alone, personally since you've gone this far which certainly isn't a five minute job and intend to keep the car for a long time then yes I'd renew all that I could.
It is very difficult to advise best course of action here though as the car is new to you with only 20 miles covered, not easy to know a car over such a short period of time and mileage.
However looking on the bright side there's a lot of members on this forum who can help you along the way whichever course of action you choose to do.
Regards
Pete
Engine out that's the easy bit. I was taking rocker off and one of the Allen key bolts had failed in side the cover so drilled the head off and left a right mess in side cover so now got to take cam shaft out make sure spotless also when I put piston 1 TDC all makings line up should the balance shafts makings line up to because thay don't and didn't notice any vibration
Thanks Pete / Simon
Thanks Pete / Simon
PSH
PCGB Member
Errr... Careful Simon, these bolts shouldn't fail, be sure to use good quality tools to reduce risk of rounding off the Allen head bolts. For any stubborn bolts try tightening them and then try undoing again, this tends to help with removal. Yes the balance shaft marks should line up, how far out are they and how is the belt adjustment? IIRC my marks were never spot on but very close. BTW I would replace all belts while your doing the rebuild and check all idlers/tentioners, also the water pump is critical, check for any sign of bearing wear. These aren't cheap but much cheaper than having to replace valves or worse if the pump fails.
Pete
Edit: forgot to add be careful removing the camshaft from the tower housing, it's easy to damage the journals which would mean a new tower as they don't have bearing shells. Also you'll need a full gasket set, do not reuse any and don't forget to replace the clear plastic washer on the camshaft and certainly don't forget to remove the old one first. These washers are nigh invisible so easily missed.
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