fraggle

OK, just about finished.

As some may remember, when I was at STIM I was having overheating issues. I had to run the heater in the car to keep temps reasonable, and really couldn't use any throttle of I was way out of luck. The side tanks were failing on my radiator, so I assumed that was it, so --

1) Replace rad with new C&R from 928 International and install new dual-fan unit from 928SPECIALISTS. - CHECK!

Put everything together AND -- still have an over heating problem. Same symptoms, but the baseline is a little better. Still need the heater on to keep things in check. PRoblems start in 4-5 miles, 10 minutes at most. I'm guessing the overheating issue overpressured the old rad and took out the side seals, so it was a result, not the problem.

SO, what next?

New thermostat, new waterpump and associated timing belt job, while I'm there I've installed the PorkTens'r as well, so now we've got

1) New rad (C&R)
2) New Fans (dual setup from 928 specialists)
3) New thermostat (75C, tested in water and it works)
4) New waterpump (Thanks Roger!)
5) Other new bits, gaskets, etc from the timing belt job.

Right now I just need to fill up the system with coolant, burp it and test it. I ruined the old rad drain plug removing it after over-torquing it in the C&R.

As soon as the plug gets here, I'll be filling things up.

I've done a bunch of searching about burping the rad, but found no Best Known Bethod.

Can anyone give me a bit of advice on this one? I want to make sure I do everything right!

thanks

aggravation

Maybe I'm just lucky with radiators but with mine, both times, once after installing a new one and the other time after partially draining the system to remove and replace the water manifold, I was able to get it full and without air simply by putting it all together and using the reservoir to fill it.
Gravity fills it slowly just keep adding to the full line and then after running the engine a while I'd open the heater valve and give the lower radiator hose a few squeezes then after a short drive add a bit more coolant as the reservoir indicated it was needed.

M. Requin

No advice, but good luck! I get a kick out of remembering chasing you on the Goat Track to the motel at SITM, you overheating and me on empty worried about churning up crap in the tank. Hopefully you're getting to the root main cause of the temp problem - keep us posted!

soupcan

This is written in the manual.

1987 Porsche 928 S4 V8-4957cc 5.0L
Vehicle Level Engine, Cooling and Exhaust Cooling System Service and Repair


Service and Repair
Notes

These engines do not require a specified bleed procedure. After filling cooling system, run engine to operating temperature with radiator/pressure cap off. Air will then automatically bled through cap opening.

User 4221

Ernie (ErnestSW) had this problem on his GT several years ago. I think it was air in the system that was causing his problems. He devised a method to pressure burp it with gravity feed that worked well.

Do a search on his issue and you may find your answer.

HTH,
Scott

Glenn M

Did you replace the seal behind the thermostat?
Glenn

SeanR

+2

User 4221

I recall this contributing to Ern's issues (mechanical, not mental)

6mil928

This what I did when I did my OB radiator last year. I also checked periodically after that and added a little as needed.

The_Remora

Wow, Fraggle man that sux! had no idea that would turn out to be such a ball buster.... sure hope this fixes it for good now. hey , at least you have a really bling cooling system now! best of luck with it and keep us updated on how it turns out.

SteveG

I've drained them 3x, no trouble on the '85 twice. For some reason the GTS didn't cooperate. Filled via res. , burped as per normal. I think I topped it off 4 times after driving, +/- a quart each time. I thought I had a leak, but nothing appeared under car or in the valley (or in oil). I did find a drip coming off the lower hose which needed another turn or two on the clamp. I was being careful not to overtighten b/c the nozzle is plastic.

Fogey1

You are looking at something more than the dash gauge, right?

I ran myself ragged and poor chasing an overheating problem that wasn't. I finally measured the coolant temp and it was fine, despite the gauge. I replaced the gauge sender and the "problem" went away. Not a 928, but just sayin' ...

fraggle

Ok, OK.

RUNS AND RUNS AWESOME.

Win for ME.

I'm extremely excited here.

Here's my fill procedure - excuse the spelling errors I've been celebrating since 2pm.

1) big funnel to pour coolant into the "in" side of the block - the cool side from the rad until it almost overflows. The waterpump should be primed at this point. Thermostat installed with little valve on UP side with new seals, both the o-ring for outside seal and the one inside the opening.
2) fill the resvior overnight and let drain into the rad.
3) Next morning, top off and fire up engine.
4) watch temp gauge depressingly climb until white line before RED with interior heat ON FULL. assume all is lost.
5) rev snot out of motor in desparation.
6) watch it eat another 1.5 gallons of distillied water.
7) excitedly dancxe around as needle drops it below bottom white line
8) take a drive and watch needle never rise more than one breadth above lower white line.
9) drink heavily all afternoon in celebration. Warstiener seems apropriate.

I'm good, shark is good, and will be on the next drive, wherever it is!

I've installed:

1) New C&R rad (from 928 international)
2) New waterpump (from 928s-r-us)
3) NEw 75C thermostat (from 928 international)
3.5) Helicoil for waterpump bolt stripped by PO.
4) New waterpump (from 928s-r-us)
5) new fans (twin-fan from 928 specialists)
6) NEW seal behind thermostat (in-block)
7) PorkT'snr (from Porken!!!)
9) new timing belt (from 928s-r-us)

wahoo!!! what a great drive.

I hope to just feed my car oil and tires for awhile!

Mrmerlin

as Soupcan has posted there isnt any fancy proceedure to fill.. a coolant system on a 928

Just follow this, fit all of the coolant hoses and fill from the coolant bottle, ( this may take a while as the coolant will be bleeding into all of the water passages)
Start the car with cap off and the heater on full, let it warm up till the fans come on. replace the cap and take a 5 mile drive shut the car off and let it cool. top up as necessary to just above the seam on the bottle. It really does work

The_Remora

Hey, congrats! Glad the beast is running nice and coool now