Engine overheating under load

[Clarkey]

So, it's an SR20DET and the issue is the temp goes up when you give it the beans. No problem at all idling.

This has to be a blocked radiator or a jammed thermostat right......
The rad should be ok, it's an enormous alloy one which seems fairly new.

I'd say it's more likely to be the stat, even though they usually stick in the open position. I think my first port of call will be to remove the stat and take it for a thrash to see if it helps.

What do you guys think? What is the best way to clean out the radiator?

Oh, already tried changing the rad cap, made no difference.

 

[Clarkey]

yeah I wanted to plug in my conzult to confirm the dash gauge but unfortunately my laptop is broken :/

 

[Clarkey]

Yeah runs fine otherwise, drive it gently and it will go all day without the needle moving.

Knackered temp sender is possible, will try to get the temp off the OBD to confirm, but the laptop is another problem altogether.
Fuelling fault also possible, the engine isn't original, it's a red top from a JDM S13 in a UK S14. Without using a wideband, how could I tell though? Likewise ignition timing could be an issue, will try to get a timing light on it.
Shot water pump I'd say unlikely but won't dismiss it, surely it would overheat all the time though?
Head gasket, there's no oil/water mixing, it doesn't spew its coolant out at all, it does sound a bit lazy when cranking though, as if the compression isn't too great.

 

[Clarkey]

Most likely water pump, is belt slipping when you load the engine? Or when was the pump last changed?

No slip, no idea when changed.

What state is the radiator in? Are the vanes overlly bent or abused?

Looks like new. Is also really huge given the modest output of the engine.

Does the heaters work if not possible blockage or air lock.

Yep, works lovely. Heater on max brings the temp down quite effectively when it goes up too.

Other than that could be blocked or partially blocked engine block water ways

 

[Clarkey]

Pretty sure it isn't running lean, the tail pipe is black and soot on the bumper too.

While I'm on the topic, the car feels slow as crap, no faster than my 328i really. Running only 9psi and there seems to be a ton of lag. The turbo on it looks like brand new, spotless, and has some braided oil lines going to it. Obviously it's had some turbo work but we don't know what. Red top had a t25 standard instead of the t28 on the s14 ones right? Will try and find some markings on it, see what's going on.

 

[Clarkey]

Seems like the problem was just a crappy dash gauge. In actual fact the engine was running too cool unless thrashed. Bad thermostat you'd think. Correct, I opened the housing to find no stat in there.

I'll chuck the new one in in a min and hopefully all will be well.

On to the performance. Found one obvious mistake, the accel cable bracket is wrong and the throttle is only opening to about 3/4 or so. Easy enough to get that fixed.

Whereabouts are the ID numbers on the turbo? I will try to find out what the unit is. Hopefully it is a t28 unit s14 spec and not the original red top t25g. I've read that the t25g is meant to have a really quick spool, this one certainly does not. Hoping to get a bit more boost out of it but not sure what is safe, I hear 12psi is safe on a stock red top.
Car has the following mods on it that I know of.
Apex'i air filter
FMIC + Big alloy rad
Paddle clutch + short shifter
De-cat + big straight through exhaust system.

Oh, and do engine mounts fail on these? I noticed the engine seems to move around a bit just while tugging the inlet pipes off.

 

[Clarkey]

This is where the dial sits now

Looks high doesn't it, but the OBD says that is 78C, pretty good for a 76C stat I'd say. I'm reading some stuff saying the S13 (which the engine came from) temp senders are different to s14, maybe this is the cause.

 

[Clarkey]

in my experience usually stamped on the face of the inlet housing in some manner.

It's pretty cramped in there, all I can see on the turbo housing is GARRET. Maybe I'll drop the hose off so I can get a better look.

 

[Clarkey]

Thanks thats a big help. Going to be hard to see the rest of the info with the thing in situ though

I turned the boost to 12psi though. I also temp removed the BOV since I suspected it was leaking. With that, a proper temp and a throttle which opens all the way it pulls much better than before. At 14psi it was getting fuel cut at high rpm though so I turned it down right away, power was savage though and it sounded mean. I'm reading that Jez at H-dev does chips for import SR's too, so that's probably the way to go once I've determined the turbo won't **** it's pants.