supracosworth

My car overheated two nights ago to over 130C because of a leaky coolant hose. I replaced it and drove home without any drama.

Then last night when I try to start the car, it'll crank and there were several attempts to start but it didn't. I thought there's not enough petrol cos the car was running on empty the night before so I filled her up with 4 litres from a spare tank. Still won't start. I hardwired the F/P and Power on the diagnostic port and there's petrol coming out from the fuel line but I don't have the guage to measure fuel pressure. As I'm doing the car alone, I can't crank and observe spark at the same time but I can hear spark jump when I crank with the leads dangling.

Now there's not even the slightest hint of it wanting to start.

While the plug was out, I tested compression and to my horror the rear rotor gives less than 40psi and even that, it's sporadic sometimes reading as low as 20psi all across 3 faces.

What I can't understand is on the night when it overheated, the car was still boosting strongly at over 1 bar. Could it have detonated without me knowing? There was no smoke no funny sound on the night when I drove it home.

Any thoughts would be much appreciated.

Rgds

Michael

Fumanchu

My coolant seal just totally blew out this last week. I almost had no warning at all. The car acted the same way as yours when I tried to start it. I'll re post when the shop tears down my motor on Monday. I can't wait to see what happened.

T88NosRx7

iTrader: (1)

That sucks, hopefully it is something small.

supracosworth

Coolant seal on my engine are gone long time ago but Blockweld seems to be doing the job until now. I checked the sparks and they are not rusty or wet.

supracosworth

Still very dead motor but I compression tested the first rotor. Surprise, 80psi on all three sides! Then it's the rear rotor's turn -- surprise, no more than 10psi on all three sides. There are sparks on all wires and there's fuel in the line though I don't know whether there's enough fuel pressure to get the injectors working. Assuming that there si no compression on the rear rotor, should the car be able to start on one perfectly good front rotor?

Snook

iTrader: (12)

I don't think so my friend
I had a very hard time starting my car when I blew the engine
I had perfect front rotor and 1 perfect side on the back rotor and the two other sides had 0.

What I had to do was floor the gas all the way and crank for about 5 seconds for it to start and then it drove very very poorly felt like I had 50hp.

You didn't blow the engine due to an apex, corner, or sideseal failure because your numbers are still even on each side of the rotor. I guess the coolant seals just totally burned up?

Sprockett

Maybe overheating DAMAGED the seals, and then with the extra strain from driving it for a couple days more, it caused the weak seals to fail. My car overheated twice due to a short in the radiator fan, but everything worked fine for another couple of weeks. Then my engine died.....so I think overheating won't kill it right away, just weakens it.

911GT2

My exact symptoms when I blew an apex seal. Sorry supracosworth, sounds like you either blew 2 apex seals and chipped one, or blew the coolant seal on the rear. Good luck, get a ported motor and you'll be happier than ever.

supracosworth

I've got a spare set of good housing and rotor lying around together and a full set of the soft seals from Rotor Resources. Perhaps I'll bite the bullet take a couple of days off and see if I can assemble the damn think myself before ordering a reman. Cheap am I? On the good rotor, should I replace the apex seal or should I just leave them alone? I'd have thought since the seal and the housing is run in or perhaps even grooved, putting on new seals might actually seal WORSE than running the old ones?

kempo

iTrader: (2)

when you overheat a rotary engine somtimes the springs on the engine (apex seals, side seals,corner seals) will lose their tension when they cool down. that may be the reason you are not getting the compression you should.

supracosworth

Where's the cheapest place to get a set of factory apex seals and springs? Not going to open up an old can of worms, but general concensus is that there is no conclusive prove that aftermarket seals, whether 3mm or 2mm are better than the factory ones right?

GoodfellaFD3S

iTrader: (213)

Put some ATF in each rotor housing through the spark plug holes and see if that helps. It'll build compression, and might unstick a seal if one is indeed stuck.....