[CLNCRXSi]

Hey whats up here my question,

I have a 92 LS DA fully built head, with about 70 miles on the motor, it was built by a knowlegable mechanic, it has a small size turbo not too sure what size it is but fairly small to make room for the A/C assembly. Anyways I was told that it would need an after market radiator, so i added a fluiddyne radiator, the car doesnt really overheat when drivien normally, boost kicks in at about 3500rpm so if driven under its fine, once the car starts to boost the check engine light turns on then a min later the temp needle starts to rise fairly high all the way to the red level. If i turn off the car the needle goes back to normal temperature level. my mechanic says it can be 4 things the oem temp cluster is giving a false reading cause when the temp is at red or hot level the engine is running normally with no signs of overheating. He said maybe the temp sensor is not working properly, or might need a aftermarket thermostat or it the way it was tuned with Hondata and might need to be retuned. From what i know the car is running rich i think, i get very little white smoke. whats do you guys think ?

Im running a stock exaust but from the headers back it has a flex pipe then 3inch piping to a stock exhaust, would getting a after market exaust help lower the temp ? i like the whole stock sleeper look and would like to avoid unwanted attention. Woul hollowing out the stock exhaust give any results ? is it worth doing ?

 

[NegroDamus]

What is the ambient outside temp when you have experienced the overheating? Does it over heat no matter what time of day or outside temps?

Things that can cause this are:
Head gasket
Head lifting
Radiator (but you have a good one)
Intercooler blocking airflow to the radiator, esp a problem with tube and fin type ICs (this is what caused mine to overheat)

The gauge cluster is fine, that some dumb ass troubleshooting by the tech, the odds of that are slim and these other things I listed are FAR more likely the cause.

DA tegs are cramped as it is, so you could have a combo of things going against you.

How much boost are you running? The check engine light sounds like a map sensor.

 

[CLNCRXSi]

10 psi
it overheat during the day even on a coold night as soon as it starts boosting, thats when the temp goes up. Another mechnic suggested that the turbo is sucking up circulated hot air from the fan due to the fan always running. he suggested i attached a custom bent pipe to the turbo with a filter at the end and point downwards away from the motor so when it spools it can get cold air. another person suggested that its the stock exhaust restricting the flow of air realease. this is a head scratcher

 

[Darkness]

it's a small turbo and only spools at 3500 rpms? how is your timing?

 

[CLNCRXSi]

been check, tuned to run safety as a daily driver, buddy club thick head gasket, would exhaust be a factor, im have a stock exhaust attached to 3 inch piping.

 

[NegroDamus]

I assume it didn't over heat while it was being tuned?

Try some shit.
Retourqe your head bolts.
Disconnect the exhaust from the downpipe/cat.
Make sure your fan turns on, or rig it up to run constantly to test if that makes a difference.

What motor did you get the head gasket for?

 

[NegroDamus]

Also check your coolant levels after it over heats. Fill the reservoir and then check it after you drive it a while. If the shit is drinking coolant, you likely have a head/gasket issue.

 

[CLNCRXSi]

this is what people suggest might be the problem

99 si head
thermostat - brother said it was replaced
head gasket - brother said it cant be has a brand new buddy club gasket

people are suggesting that it might be
headgasket
thermostat
turbo spooling and taking in hot air not enough cooling
could be that i still have the stock exhaust
timing on the belt
too much boost

when it overheats now with the new radiator the resoviour is still the same no gurgle or spilling, fan is rig to start with the ignition so it is always running.

 

[Darkness]

im really interested on this problem.. not that i have an answer but i want to know what really is the problem and the solution..

ok...... and the point of that post was :confused

 

[MortsAccord]

Just because it has a new head gasket doesnt mean that it was installed correctly.

My thought is its the thermostat/waterpump combo, A thermostat has to have pressure against it to work, if a non oem thermo was put in there it could cause cooling issues. If it was removed as some idiots do to theoreticly "increase cooling ability" your car WILL overheat when driven at anything more than light throttle. Thermos increase pressure resulting in higher boiling temperatures.

I would drain and flush the cooling system throughly, with the heater on high. Then I would re-fill the system. I would also see if running the heater would help the temperature problem, which would show where the flow of water is being effective. Coolant smells funny too when its burning through the exhaust.

I would think theres possibly air in the system preventing it from working effectively... water pump cavitating?. Maybe a pinched hose somewhere restricting water flow. The fact that you said you had VERY LITTE WHITE SMOKE sends me a red flag, as blue smoke is oil black smoke is rich and white smoke is coolant leaking.

Thats my thoughts.

If the cooling system was workign as it should the turbo taking in hot air as it passes through the radiator wouldn't matter a whole lot.

 

[CapnToll]

Double check the water pump as well. Coolant flow velocity plays a major role in how much heat transfer occurs between the coolant and the rad. Also as mentioned before, the ram air to the rad that is being blocked by the intercooler is also an issue...but as long as you don't have a jumbo intercooler or your rad/intercooler fins aren't bent blocking the air flow, you should be okay.

Definitely check the thermostat....you could just as easily be recirculating the coolant through the engine with it never going through the rad.

If you want to experiment, you could try cranking your in-cabin heater. That will remove some of the heat from your coolant as it passes through the heater core.

EDIT: Oh, and if you actually want to know if you're really overheating, get your hands on some thermocouples and the meters. Slip the couples into your coolant tubes (inlet/exit), and record the readings. You don't want the coolant exit temperature to go beyond 190 F.

 

[CLNCRXSi]

Damn guess what, i change the stock exhaust and added and ES Technic exhaust, now running 3 inch piping all the way and viola! no over heating, no check engine light not nothing, boosting @ 8 psi with A/C on and nothing, I cant believe that something so simple can make a difference. Guess the motor was being suffacated. BTW the ES exhaust sounds awsome, sounds VERY VERY stock no rice sideaffect....LOL....thanks for you input guys ! Im still going to keep on eye on the temp though just in case.