Gsx engine bay very hot

[clbailey]

My temp gauge sticks right in the center but I've noticed the engine bay gets very hot. Can't even touch the valve cover for more than a Milli second without it hurting. Is this supposda be this way?

 

[LandoAWD]

How hot is hot? Numbers, not anecdotal measures...

 

[bryanwheat]

Sounds about normal to me.

 

[Colt4G63 also]

I think the 300-400 degree oil that's spraying all over the inside of the valve cover probably causes that, so unless you are wearing gloves, that's probably normal for it to hurt.

Intresting factoid: Hot oil was poured on soldiers as a weapon of mass destruction in the medieval times.

 

[agentorange313]

My temp gauge sticks right in the center but I've noticed the engine bay gets very hot. Can't even touch the valve cover for more than a Milli second without it hurting. Is this supposda be this way?

I am assuming that you are talking about the stock dash gauge:

All that gauge provides is a danger "area" for the temps. There is no quantitative information from that gauge, meaning you can not extract any data beside, cold warm and hot. The gauge could also be malfunctioning.

Now the question is what temp is your car running at? Aftermarket temps gauges can tell you this, or some datalogging software (plus the hardware if needed). That will help you determine if you car is running hot.

My engine temps have seen 210 at idle.....my 1g runs hot, DSMs run hot. We have a turbo sitting in the front of the engine building heat from the exhaust gases.

Your valve cover should be hot, it should not be cool in any way. In fact if should hurt when you touch it after your hoods been closed and you car is running warmed up.

 

[1983gsp]

Temp gauge on the dash is just a tic mark right of center when my logger shows 206°f. Dead center is 220°f. 1/4" past center is 230°f. This is all on my 1g for reference.

 

[gofer]

I think the 300-400 degree oil that's spraying all over the inside of the valve cover probably causes that, so unless you are wearing gloves, that's probably normal for it to hurt.

The oil better not be getting that hot, Jesus.

Odds are its the exhaust manifold/o2 housing heating up and heat soaking the engine bay, by chance do you have any heat shields installed?

 

[97GSXBOOSTIN]

I was really thinking of putting a vent in, in my hood to try and combat some of the heat under there. I just don't want it to look like crap.

 

[Leonthefaded]

Well if you do not have a heat shield installed on your exhaust manifold, or o2 housing odds are that your engine bay will get pretty hot. I would considered heat reflective tape or something to insulate the heat in your engine bay otherwise the paint on your hood is going to begin to ruin very quickly.

 

[pauleyman]

heat soaking the engine bay

What does this mean objectively?

 

[007jimmy]

Heat soaking will cause EVERYTHING in your engine bay to get hot. Sensors, wires, lines etc.... This can lead to premature damage to a number of things and even cause your car to run poor. The ECU starts pulling timing when the coolant gets too hot. I re-installed my heat shields and took care of my coolant system properly for this very reason. My o2 housing with no heat shield caused my alternator to die twice. If not taken care of it could get costly..

 

[gofer]

Objectively it means that, with the increase in under hood temps, its going to increase intake temps and potentially make the car slower. That's why there are heat shields on the exhaust parts from the factory, it keeps the heat out of the rest of the engine bay where you don't want it.

Like Leon mentioned, too, running without a heat shield on the exhaust manifold can cause the paint to bubble up on the top of the hood.

 

[whiteboyz]

What does this mean objectively?

Simple terms - a hunk of metal (or other thing) starts out at ambient temperature. It's exposed to other another temperature that warms (or cools) the surface. As time goes on, the head (or cold) evens out throughout the metal and the thing is "heat soaked". If you take away the source of the heat (or cold), the part will remain hot (or cold) for quite some time as it gives off the heat (or cold) that has "soaked" in the metal.

In terms of intercoolers, as the compressed air is compressed, it gets warmer. As it passes through the intercooler, the air gives off heat to the intercooler. And the intercooler gives off that air to the outside air that passes over the intercooler. After a while, the intercooler "heat soaks" and can't absorb as much heat from the compressed air to cool it. The temperature of the compressed air to the engine goes up and that increases the chance of detonation in the cylinder.

Sitting idle (with no air passing over the cooler) can also raise the "heat soak" causing loss of performance (or detonation), but it will reduce the "heat soak" as the car is moving with fresh (relatively) cool air passing over the intercooler again.

The same thing happens with cooling systems. The combustion chamber temperatures can get quite high, and the coolant passing through the cylinder head carries away the heat. But when you turn off the engine, there is still a high amount of residual heat in the chamber material that has not been removed. That heat "soaks" the head (and the coolant) and makes localized hot spots - the normal coolant temperature may be 195 degrees, but that local hot spot can easily get to be 20 - 50 degrees hotter. That's why many cars have a fan that will kick on after the car is parked if it detect that the engine is too hot.

 

[pauleyman]

I just wanted to see what answers I'd get. I hate the term "heat soak". It's not objective. Heat shields keep quite a bit more heat in the exhaust instead of into your engine bay. You're not hurting anything. If you're bummed about having to wait to long before shutdown then stick a box fan on the motor after shutdown. Don't set a plastic fan directly on it. put 2x4 or something down. Works very well I think.l

 

[clbailey]

I have the o2 heatshield on but the car never had the Turbo one when I got it. I think it is just heat soak just probably never payed attention to it.

 

[dsmfa9nutter]

I've found that a free flowing exhaust helps as well as removing a lot of plastic shielding from under/around the engine bay to remove heat. You can also washer your hood/remove the rubber seal at the cowl, this will let some heat out as well. If you REALLY want to cut the heat down, wrap your turbo hotside, coat the manifold, use a heat shield, and wrap your downpipe. This will cut your temps down by 40% easily.

 

[91stocker]

If your looking to lower engine bay temps and/or iat's, there is a recent thread on just that with some great suggestions and ideas.

http://www.dsmtuners.com/forums/newbie-forum/429847-high-iats.html

 

[gofer]

I just wanted to see what answers I'd get. I hate the term "heat soak". It's not objective. Heat shields keep quite a bit more heat in the exhaust instead of into your engine bay.

Heat shields keep A LOT of heat in the exhaust, that's their purpose. Heat in the exhaust has no negative effects on the way the engine performs, heat in the rest of the engine bay does, though, which is referred to as heat soak.

How isn't the term "heat soak" objective?

 

[pauleyman]

Heat soak is a made up term that loosely described heat transfer principles. What is more objective is heat/energy, rate of heat transfer, etc. What people describe as 'heat soak" is typically involving something that is made to transfer heat from one medium to another but cannot do so because of a change in one of the above objective items. So....what can we change? Temperature of the incoming medium via change in direction. Change in rate of the cooling media, fans, CFM increase etc. Change in one of the three modes of adding heat to an area, shielding, wrap etc. Can you objectively measure a change in underhood temps at the same air temp and rate of exchange? Yes. Can you measure "heat soak". No. That's why it's not objective.

 

[gofer]

Heat soak is objective and I can (try) to prove it.

I'll use the fuel pressure solenoid (FPS) as an example here since it was Mitsu's fix to fuel vaporization in the fuel rail which was caused by heat soak. In the case of measuring heat soak in the fuel system you can measure temperature of the fuel in the tank and then take another temperature reading of the fuel in the fuel rail, then compare the differences in fuel temps.

Granted, Mitsu didn't install a temp. sensor to check heat soak conditions comparing the difference in fuel temps between the tank and the rail but they did incorporate the FPS to fix vaporization in the rail which is caused by heat soak.

 

[LandoAWD]

I've found that a free flowing exhaust helps as well as removing a lot of plastic shielding from under/around the engine bay to remove heat. You can also washer your hood/remove the rubber seal at the cowl, this will let some heat out as well.

This change will only help at idle/low speed. Once you get moving, you've essentially got a cowl hood and you're sucking air IN from the raised rear of the hood. There have been a few heated arguments over this that I've seen, but tufting the hood is all the proof you'll need.

 

[BoostedDSM75]

Engine temps for me run around 205-210

 

[Leonthefaded]

How do you guys measure your engine bay temps? Do you have additional Sensors?

 

[AK Maniak]

Heat soak is a made up term that loosely described heat transfer principles. What is more objective is heat/energy, rate of heat transfer, etc. What people describe as 'heat soak" is typically involving something that is made to transfer heat from one medium to another but cannot do so because of a change in one of the above objective items. So....what can we change? Temperature of the incoming medium via change in direction. Change in rate of the cooling media, fans, CFM increase etc. Change in one of the three modes of adding heat to an area, shielding, wrap etc. Can you objectively measure a change in underhood temps at the same air temp and rate of exchange? Yes. Can you measure "heat soak". No. That's why it's not objective.

Umm no.
Definition of objective: Not influenced by personal feelings or opinions in considering and representing facts.
Heat soak is a term used to describe something, that doesn't it make it subjective.

 

[2literking]

do you have an aftermarket coolant system? get some nice fans, an oil coolant system and a Mishimoto Radiator and you'll be good.

do you have an aftermarket coolant system? get some nice fans, an oil coolant system, and a Mishimoto Radiator and youll be set.