Not a good day today guys, Im in need of you FI boffins to help me diagnose a fault with my built APS TT car.

Background.

Driving along motor only has 1400 miles on its break in map, rev limit 4.5K and 0.35 bar boost. I start and stop from 3 sets of cross roads reving to about 3.5-4K 1/2 throttle. Stop at the lights and notice the coolant temp on the OEM gauge is above half way? Ive never seen it move before ?? (defi oil temp reading 80C) start moving again and it drops back to normal. 100m down the road I stop for more trafic lights and the gauge starts to rise fast. I pull over before its goes in to the red and jump out pop the hood and find that the coolant overflow is pissing out!!

Ive shut the car off and let it cool and it glugs all the overflow back in untill it went empty.

I got on the phone to the builders of the motor and I said i think it could be a head gasket? It has a HKS gasket in there. The motor builder thinks its not a HG problem due to the fact its not running much boost and rev limited?

I topped the overflow up with drinking water and started the car again, it went to hot in a few mins.

Towed the car home and tryed bleeding the coolant system. I topped the rad up with a spill funel and rasied the front of the car and disconected the turbo water return to the top back heater hose.

After a few mins of topping the system up i had water coming out the top hose.

The heater was blowing cool ait when on full hot showing an air lock i think? Ive got the heater blowing warm air now but not very hot as it should.

Idled the car for 15mins and the overflow tank overfilled again the oem temp gauge can up to normall op temp and did not move. The fans kicked in and out a few times.

I took the car for a quite 5min drive round my house and temp stayed in the normal postion on the gauge.


Any ideas guys Im freaking out as the cars not even run in yet!! lol..

Fingers crossed its just a mad air lock as the car runs fine and oil has no water in and no sweet smell in the exhuast fumes.

HELP please!!!

 

Do you have the spill free funnel for releasing air? I think you've got the possibilities covered in your post.

 

Keep bleeding.... Sounds like you have air....

 

Thanks for the replys guys. Ill bleed the car again soon. Its just strange the car has run great for 1400 miles to just go mad like this for no reason? Do you think having the down pipes swapped out to heat wrapped APS 3.5" ones could have anything to do with this??

I know its very very unlikly its just I had the DP's fitted yesterday and the car did this with in 60 miles of having the new DP's on?

 

Did someone disconnect a coolant hose and reconnect it when they installed the downpipes? Air got in there somehow and I also doubt it's the HG...

 

We need an overheating/coolant bleeding section of the forum.

 

I think you just had a traveling air coolant bubble in the system.I have had the same thing.

 

I really hope so.

 

Doesn't sound too strange. Like others have said, sounds like some remaining trapped air. Best of luck.

 

Ive worked on the car today guys and bleed the hell out the system. Rasied the front end and used a spill funnel in the rad while heat cycling the engine. spent a few mins reving the motor 1k-4K RPM and was getting tons of bubbles out the rad funnel. Topped up coolant as i was doing this because as the rad funnel was bubbling it was sucking coolant back in.

Bleed the rear heater hose a few times and did this process twice letting the car cool for 30 mins in between.

Heaters in the car now blow very hot air as they should. Took the car out for a test drive and the overflow tank level came up a few inches as it sould but stayed about 3" from the top of the tank. OEM coolant temp gauge was rock steady, gt the car up to aboout 100C oil temp which is quite hot fot the car now as Ive only had it hotter on the wales run and so far no problem.

Ill check the car over again tomorrow afternoon and top up the rad if needed. Bleed the back hose again too.

Fingers crossed the problem was just caused by losing the level in the overflow tank and pulling air back into the system.

It may also be the fact the coolant is boiling in the turbo's when the car is shut off and this air has accumulated over weeks and cause this problem??

Im hoping that this shows no sign of a headgasket problem as the car pulls like a train, has no white smoke from the exhaust and did not puke any coolant so fingers, toes and eyes crossed it wont happen again.

Mark/Tony what do you guys think if your reading this??

Ps. Ive also ordered a new Nismo rad cap from sarah so that will rule that one out too.

 

Did you open the green bleed port when you topped off the rad? See picture.

 

On the APS TT Kit that is removed and a junction is in place for the water line for the turbo.

 

I still had a rear bleed valve with my kit. OP, I would reccomend trying this bleeder as well if it is still on your car. Otherwise it sounds just like the others have said... you have an air pocket in the system. It also sounds like you have bled it out if the heater is blowing hot air again. Keep an eye on your temps and consider getting an oil cooler just to be safe

 

Ive got a -12an lined massive oil cooler mate, thank for the heads up. Sorry to hear about your motor mate. The blled valve is removed but so far so good guys.

 

Didn't know that. I cut the line and spliced in a tee on mine, hence why I still have the bleed valve. It's handy in these situations!