hey guys,

Got a 98 Trans Am. I removed the radiator baffle shield long ago and I noticed now with the weather getting very hot the car starts to overheat when idling or stop and go traffic. Is this baffle shield required?

On the freeway car stays cold 180-185 degrees


Car has new LT1 radiator
Motorad 180 tstat 3 months old maybe sticking?
Brand new fans
brand new upper and lower radiator hoses(mishimoto)
coolant changed every summer. Bled for over an hour
original WP from 98
Brand new radiator cap (ac Delco)

 

When cruising on the hwy the air dam is doing 100% of the cooling. When stopped, slow, traffic....the fans are almost 100% of the cooling. If that part has anything to do with the directing of airflow into the radiator then yes, that could be the problem. You could also have one fan failed.....you could also have an issue where your fan(s) are not switching into the HIGH SPEED setting. ((I know they are new,,,,check them out)

I'm not really sure about that part as I would have to look under the car to see how it fits into the whole factory set up and how it would affect the normal flow of air when the fans are ON and sucking as much air up into the radiator as possible. If its allowing a larger than normal opening when the air can't be properly sucked in.....then that will hurt you at low speeds.

 

Also, is the rest of your factory shroud in place properly? That will absolutely cause overheating at slower speeds and idling while parked.

 

Not to be Captain Obvious or anything, but...

If I had a car that had cooling issues, and I KNEW there were cooling parts missing off of it because I had taken them off myself, I believe the VERY FIRST THING I would do, even before posting on the message boards, is put the missing pieces back on and see what happens.

 

Yes. Reinstall it. It is critical especially in the summer when using the AC.

Its function is to create an envelope or ductwork pathway for the air directed up from the air dam up thru this ductwork and then thru the ac condenser and then thru the radiator. Most of the air to radiator goes thru this pathway and the better you can seal it the more efficient it becomes.

Be aware that most of the air that gets directed to the radiator must pass thru the ac condenser first. So if the ac condenser is plugged then it restricts air to the radiator.

Unless you have cleaned or replaced the ac condenser recently or if ever it's likely that the bottom 25 to thirty percent of the bottom of the ac condenser and perhaps the radiator as well is plugged with debri. The restriction not only blocks air from moving thru the condenser and on to the radiator, but it reduces the efficiency of the ac condenser as well.

Don't know or can't tell if you opened up the front bumper cover, but if you have, then all bugs and debris got to the ac condenser, whereas if the shielding had been left intact and in place the plastic shielding would have kept bugs and debri from getting into the ac condenser. Yes, there will be some bugs that get sucked up into the air duct, but not nearly as many as what crash into your front bumper cover and grille.

Replace the shielding that was removed and inspect and clean the ac condenser. You will probably have to search for salvage cars if you threw the original ductwork away,

BTW and FWIW the shroud around the cooling fans works the same way. The shroud isolates all air from the front of the radiator into the shroud so the puller fans only draw air from the face of the backside of the radiator.

 

Thanks for the feedback guys.
Upon reinstalling my new LT1 radiator i cleaned out the AC condensor very good with a high pressure air compressor. I cleaned it for about a good 30-45mins, getting out all the little pebbles, dead bugs and dust/dirt.

As for the radiator baffle I did pull that out a coupe years ago and its been fine since up until a couple months ago.
Fans are working fine. low speed\high speed.

Yes the factory shroud is still in place.

I will go ahead and get the radiator baffle from hawks and pop it in and go from there.

**updated things ive done, that I forgot to add

Car has new LT1 radiator
Motorad 180 tstat 3 months old maybe sticking?
Brand new fans
brand new upper and lower radiator hoses(mishimoto)
coolant changed every summer. Bled for over an hour
original WP from 98
Brand new radiator cap (ac Delco)
** all new cooling fan relays
** I have a new ac delco coolant temp sensor, that I will be installing today and I will bleed the car some more

 

yes the factory shroud is still in place. thing is i removed that over a couple years ago. and recently i had to start driving the car every day due to my daily being down. about a couple months of dailying the car is when this started to happen it was fine prior to that. I mean I am still going to put the center baffle back in its place im legit stumped here

 

Also another quick update of what else I've done

Car has new LT1 radiator
Motorad 180 tstat 3 months old maybe sticking?
Brand new fans
brand new upper and lower radiator hoses(mishimoto)
coolant changed every summer. Bled for over an hour
original WP from 98
Brand new radiator cap (ac Delco)
Brand New AC Delco coolant temperature sensor
Brand New Ac Delco fan relays

I've noticed this happens overheating happens more also when the AC is on. so im guessing maybe the ac compressor is going bad as i noticed it is leaking oil from the middle of the case, it's been leaking like that for a couple years now just never thought anything of it.

Im going to bleed the car some more also this time by unbolting the driver side of the steam tube. is that okay to do? a straight flow of coolant should come out of that correct?

 

A leaking compressor won't cause you to overheat, it will just shut down at some point when the refrigerant gets too low.

Is your coolant level ever a little low when you remove the radiator cap to check it (cold engine)....?

Why don't you check to see if your t-stat is opening all the way. Its definitely opening to some degree otherwise you would overheat in 15 minutes and it would never run cool..... Drop it into a pot of boiling water with a temp gauge in the water.....see if it fully opens right before 180*F is reached. Should be fully open by 180*F.

Or....radiator cap off (cold engine)...start it up.....then wait till you see the coolant start to move after it warms up (10-15 minutes). And verify the cross-over tube is spitting water out right inside the radiator cap neck.

And as I said in my first post....I'm not sure that lower baffle has anything to do with helping the air flow at low speeds or in traffic.....I'd have to look. So you could have another problem causing this since you said you drove around for awhile without overheating and the baffle was not in place.

What do you mean...drivers side steam tube? You mean the cross-over line coming from the head that attaches right under the radiator cap? And that cross-over tube should be connected the lower of two ports going into the radiator cap neck....just in case those have been switched.

 

Coolant level is always the same when the engine is cold.
I do notice when the engine is cold and i turn the car on with the radiator cap off to bleed it coolant is flowing out of the radiator neck. that is normal correct?
Also im guessing this may then be an issue with my thermostat as it fully opens at 204 degrees. I verified this will a pricey OBD2 scan tool that records live data. I noticed the coolant level in the radiator dropped at about 204 degrees. so im guessing that is too late? although i kept seeing on some posts that a thermostat fully opens 10-15 degrees from its temperature ex. A 180 degree tstat opens up at 190-195. so would you say mine is fully opening way too late?

yeah thats what I meant the steam tube thats bolted on to the head. can I also bleed the car by unbolting that slightly?