Mrmerlin

get an IR gun at HF they are about 29.00 on sale.
then you can aim it at the hoses and the water bridge to verify thermostat opening and coolant temps. Its possible that the ground on the pod is bad and it gives a false reading

Lizard928

I have seen many faulty new thermostats. So dont rule that out.

But Stan's suggestion for cleaning the grounds for the dash (and engine) are a wise idea as what you are seeing on your temp guage sounds like either a bad ground, bad thermostat, or waterpump.

What I would do though is to go to home depot and get an expanding plumbers plug of the right size and to remove the thermostat. With the thermostat out put the plug in the hole that the rear plate of the thermostat blocks off and expand it by tightening the nut to prevent any coolant recirculation. Then take the car out for a drive and see if you have the same symptoms. If you do I would think hard about inspecting the waterpump. After confirming temps with an IR temp guage though.

fraggle

Thanks everyone.

I already have an microsized IR gun I use for tuning nitroRC cars. Indespensible tool!

I'll report back with what I find. At last year's frenzy it was definately hotter than the other cars there, but that was before the rebuild. I haven't checked temps this time around yet.
It would be great to find I have a flakey gauge.

I've cleaned and buffed all the engine compartment grounds with 220grit.

The plumber plug thing is a great idea for testing, too.

fraggle

OK. Fired up a thread on cooling baselines for the data I collected on the temps.

Drove the backroads for 60 miles today after work.

Installed stock chips.
Disabled flaps.

What a drive. It is much faster than before. It'll chirp into second, almost again in third. It has never been this powerful as long as I've owned it.

The good news! I cannot drive it hard enough on the street to get it to overheat!

I'll need a track day to work out the rest of the bugs.

The bad? Still some heat surging, but never above the second line. Last 20 miles was very stable, maybe it was still burping out more air at the beginning. Never again rose above half way.

It also will surge sometimes, then randomly die at idle. Not sure what that is.

In all, I've now got a driver. Time to start burning up some tires.

H2

Fraggle,

So...in the end...what was causing the overheating? What did you do that made the difference?

Harvey

fraggle

This is a rough question.

I think the short answer is "excessive storage".

The drawn out answer involves a domino effect of failures.

1) Borderline headgasket due to long storage and previous neglect.
1.5) Cooling Flap fail? Needs confirmation.
2) Sketchy aftermarket chips and not enough octane/crummy ethanol fuel+weak headgasket. It was pinging like crazy under 3/4 throttle. Rebuild improved this, but with the swap back to stock, this behavior is gone.
3) Rad End tank fail, probably accelerated by borderline head gasket.
4) Massive overheat en route to SITM08.
5) Complete head gasket fail and head warpage.

I'm going to try re-enabling the flaps this weekend. Chips are staying stock until an ST2 wanders into my life.

Thinking a bit more, the ping and the heat wasn't that bad until after my first timing belt job. I discovered the passenger side cam gear off a full tooth. I'll bet that was protecting the motor from the agressive timing curve introduced by the aftermarket chips. Maybe I blew it up by fixing that.

H2

Thanks, Fraggle. That gives me something else to think about. My S4 is missing the front air duct. I'll install one of those and see if that makes a difference (some say that it will)...I may try the chip change if this doesn't work. I just slightly overheat on vigorous driving...but headgasket is fine. Radiator and thermo perfect, etc. I may check my belt teeth setting too. I drive everyday but it just needs a little something extra for the track. I've tried all the usual stuff suggested here.

Again, thanks.

H2

fraggle

I hate my car today. I think I still have overheating issues. Unfortunately it hasn't caught fire so I can't make an insurance claim and give up.

For reference:



15 minute drive, normal in-traffic in city area (stoplights, etc, 35-45mph) 82F ambient, P2 ends up 202F with P3 at 175F. Needle is above the top line.

Yesterday I took a hard 45 mile drive in 75F ambient, gauge got to the top line, but never this high. Speeds were 45+ (sometimes +++) with a "cooldown" on the freeway back for 15 minutes. P2 was only 185F, P3 at 152F.

I need to calibrate my little IR gun with someone else's, but the trends I'm seeing on this aren't encouraging.

I'm drinkin my grolsch minikeg now.

ew928

Boil some water. Point IR gun at pot/water.
Should be around boiling point. No?

And point gun at ice cube tray should be around freezing point.

dr bob

Should be whatever the temperature of the ice is, somewhere less than 32ºF at sea level assuming the water was reasonably clean. My home freezer is set to 0ºF, for instance, and the ice in the tray is that temperature. To get a 'freezing' reading around 32ºF, put ice cubes in a glass of water. The surface of the ice cube in the water will be about 32ºF.

SMTCapeCod

Boomerang.

I hate threads that don't post the final answer!!!

fraggle

Haha! Thanks for the bump.

My final problem was two fold.

#1 - one of my fans had a broken connection. One Fan = Ok at idle. Bad at throttle!!
#2 - replaced all the transistors in my fan amplifier.

My car runs awesome now!!

Katacus

Wow...not sure if Im looking forward to my engine pull.

Bilal928S4

Fraggle,
Do you have a write up of the amplifier rebuild? I think mine is shot also, and what parts did you change and where did you source them from? Pictures?
Thanks
Bilal

Mrmerlin

another thing to consider for running hot is the MAF.
had a customers car that would run OK till he went up a long hill then it would start to run hot.
we did everything short of replacing the HGs
finally the car sat for a winter in the garage then it wouldnt run ,
did a few things such as new plugs and brains and on and on,
Finally got a new MAF the car runs perfectly no more overheating up the hills