Rated R

I'm starting to have an engine problem with my s4 fc.
First of all, the specs of the engine. It was rebuilt ~15k km's ago with new housings, 3mm seals, huge extended port, ported intake manifold. s5 Hifo turbo and Microtech MTX-8 running at 15psi. The air pump has been taken off and omp is wired open.

There hasnt been any problem till a few weeks ago when it wouldn't start. All the plugs looked fine except the trailing plug on the rear rotor was covered in fuel and oil. I changed all 4 plugs and it fired right up.

Since then it has been hard to start. From cold it normally takes about 5 secs of cranking for it to start. Sometimes both rotors will start and it'll be fine and others only one rotor will start and i'll have to hold the revs at ~2k for 5 secs or so till both start running. Once the engine is warm it will start up straight away.

My coolant level is slowly droping at about 100ml every 300km. When it starts there's is a faint smell of coolant but no white smoke. Normally when it started there was the usual puff of oil smoke then it cleared up but now there's a faint ammount of blue smoke comming out for a minute or so that can been seen at certain angles.
Driving the car round the temp sits on 180-190 on the highway or general driving round without a problem but as soon as I start constantly boosting like going up a hill the temp guage starts to climb. I've had it up to 215 degress before I stoped boosting and it got back down to 180 in about 1 minute.

Based on these problems I assumed a water seal was going so I checked the compression and it's ~95psi on both rotors which I was told is fairly good for an engine with major porting. Then I tryed a leak down test @ 90psi and it stayed at 90 for 10 mins before we took it off.

Does anyone know what the problem could be? Based on the compression and leak down tests it couldn't be the water seals or is the seal only just starting to go under high boost pressure?

Looking forward to hearing everyone elses opinion. Thanks!.

Rated R

Sorry, I double posted. I don't seem to have permission to delete this one either?

Wankels-Revenge

Did you try the geyser test? Take the coolant filler cap off, then start the car. If coolant comes gushing out from the filler neck, your coolant seals are gone.

Just to add another question...would bad coolant seals affect the compression that much? I'm just interested to know is all....

rexman13b

iTrader: (7)

yeah sounds like water seals to me too. i have a car that would start up on one rotor and then the other rotor would start up too after a few seconds. if it's not the water seals it could be a cracked iron housing letting water get in til it warms up, which would expand the metal causing it not to leak as bad.