Jaxem

iTrader: (3)

So DD my bird during the winter in 30-45 degree temps, not many opportunities to open her up, but did so the other night. I had glanced down at my gauges beforehand and my coolant temp was at a cool 170 or so, and after running it up to ~6000 in one or two gears, i look down and i'm around 190-200.

Seems like a big jump for such a short pull to me, i'm running 30# red tops with a CC503, so kind of assuming i'm not maxing the injectors, so i'm curious if this might be an indication of a weak old fuel pump that can't keep up at higher flow maybe? leaning out and heating up? or if this is totally normal?

I've got a racetronix kit ready to go on (hotwire kit is already on the car even), just haven't taken the time to do it yet, but this could definitely change that.

Have done it two or three times in the last week, same results each time

hrcslam

Does the temp drop back down right away? What speeds did you get up to?

bowtienut

iTrader: (1)

What thermostat are you running?

Jaxem

iTrader: (3)

Running a stock tstat, so I'm guessing the coolant temp was right at 180 or so to begin, from 15 or so I pulled up to around 50 or 60.

I'll have to look at where I have my fans set to come on in my tune currently, but I know it's much earlier than normal. I was still driving at at least 40 after the pull, but the temp seemed to stay up longer than usual. Could just be my own paranoia making me think that though. I'll have to hook up my laptop and get a data log of this happening

bowtienut

iTrader: (1)

sounds like normal behavior this time of the year to me. bypass flow and heater use is enough to take temps below the tstat value until youre using some power and generating enough heat to keep it at steady state.
Also your tstat sees a different coolant temp (different point in the loop) than the gauge sensor in the cylinder head does. The gauge will respond a lot faster to sudden bursts in power production, since most of the heat is generated right there in the cylinder head.

Jaxem

iTrader: (3)

I guess it would make sense with sensor placement and the tstat probably not being open, i'll stop worrying about it so much, thanks for the tip

hrcslam

Your condition is not normal. Last time my coolant temp did what yours is, my water pump spline drive was slipping at high rpm.

I'd start by making sure your radiator is clean of obstruction and the system is properly bled.

Jaxem

iTrader: (3)

The system itself is free of obstruction and filled/bled very well, but i could see what you're talking about being the cause:

When those start to go, is it just the coupler that gets wiped out, or does it take the splines on the pump and cam driven gear with it? When i had the engine apart in the spring the coupler looked marginal, but it still seemed to grab okay, so i greased it up and slapped it back on...also, the WP is original with 151k on it, so it could just be going.

Not my favorite part of the car to work on, but if it needs replacing...

Lt1Porsche

iTrader: (6)

The max temp you observed seems normal to me.

ACE1252

Hmmm, I'm not so sure that a 20* jump for a brief couple of pulls to 6000 is normal.

With my CC503, my temp actually goes down when I go WOT from cruise. The mixture fattens up which lowers the head temp.

After my CC503 install, the engine went from running around 190* at cruise to 210*. About a year ago, I put a 160* stat in the car. It now runs at a cool 180* at cruise. Runs better at the track...should have done it when I put the cam in it.

I'd for sure keep an eye on that.....the splines being stripped(and slipping under high load) might be a real possibility.

bowtienut

iTrader: (1)

It seems most here haven't picked up on the fact that his "higher" temp is actually correct for the stock thermostat. It's not a "20 degree jump"; it's not being at a steady state coolant temp before his high power blast.
If it does the same in summer temps, then I'd be concerned.

shbox

Sounds more normal than abnormal.

ACE1252

The range is normal, but I've never seen my temp jump up 20*(from a steady state cruise) just from rowing through the gears briefly.

hrcslam

This. Especially when it's that cold out. I could see it jumping 20° going from a steady idle through a full 1/4 mile drag when it's 90° out. But to 60mph in 30° weather? No. Something isn't right. And it'll get worse as the ambient temps rise.

hrcslam

I agree that the temps he is seeing is nothing to worry about, right now. But the jump in temp under his conditions is.

SS RRR

iTrader: (2)

First place I'd look is if there is air in the coolant system. Your car still has the air dam in place, OP?

BALLSS

OP

given how cold outside temps were...a 30 degree jump after 6k pull bringing it up to what would be "normal" engine temps under those RPM's seems OK

...with that said I would keep an eye on temp when outside temps are higher. Your note about your spline "looked marginal" does bring up possibility the WP is not matching engine RPM's

FWIW when I run 1/4 mi it low 50 degree temps the car idles in staging lanes around 170ish. After the 1/4 mi WOT temps are around 185 (160 stat). Even when outside temps are 100 degrees at the track it really does not get any hotter

I have a EWP

if you think you may be leaning out at WOT....you really need to have a FP gauge you can see while under SUSTAINED WOT. One tool you should have in your tool box. 15 years ago I bought the Hypertech one for about $30....I see they have basically doubled in $ now but something like that is very helpful when doing diagnostics in reference to wtf FP is.

Jaxem

iTrader: (3)

Air dam is in place, I don't think there is any air in the system, but I can bleed it again to make sure.

If I had air, I would think my temps would be high under other conditions as well. It behaves picture perfect besides during the noted circumstances

hrcslam

Usually air in the system makes the temp drop with thtittle input.