I recently discovered leaks from hoses connecting to the coolant valve and TPI TB and have long been thinking of cleaning up the hoses on my engine bay from all those ugly hoses on the passenger side.

I went through a lot of posts but none have my combination which is heater core, valve, TPI TB AND oil sandwich cooler. Currently I have lower rad to pump, top tstat housing to upper rad, tpi front nipple to tb, tb to valve, valve to heater core, heater core to metal tube on passenger side frame rail, going in a T towards the coolant valve and to the oil cooler, oil cooler to passenger side radiator (small outlet).

My plan was to go from the manifold front nipple directly to the oil cooler which goes back to the radiator small outlet. This would have allowed me to remove water from the TB, remove the coolant valve, hoses to/from the heater core and the metal tube all together.

But searching on this and other forums some were saying that going from the front of the intake nipple directly to the rad might disrupt the water pump flow as some water might flow this route rather than using the larger hoses. This post didnt have the oil cooler in the equation though.

Any views on this? Can anyone let me know also the thread of the TPI front coolant nipple as I will try and get a 90 degrees outlet instead of trying to find a bent hose?

 

It's pipe thread. 3/4NPT or 1/2NPT, it's been a few years. Reasonable chance that when you go to unscrew the stock fitting, it might rip the threads out of the intake. Steel threads in aluminum, these things can, do, and have happened.

Might be easier just to bypass the oil cooler while you're at it. Or run the intake right to the top port of the waterpump if you have the port, or plug all the ports.

 

I just came from the shop and bought a 1/2 NPT angle fitting and a piece of hose to go to the oil cooler. Now your comment is putting me off!! Wouldn't like to end up in a situation where I have to fix the intake!!!

I do have a new spare pump that I bought a while ago with a top port (Stewart Stage 1 EMP 13123) but wouldn't removing the oil cooler be a bit of a waste? Isn't the oil cooler effective?

 

It's debatable. Cooler/warmer, and with half the circuit deleted, you'd have to try it and see.

If the threads strip, tap the next size larger and away you go. But as a general rule, as had as the last couple I removed were stuck, and that was over a decade ago, I wouldn't fight very hard with a fitting that doesn't want to budge. Just be careful and know when to abandon hope of non-destructive removal.

 

You were too convincing (talk about FUD) 😀

I decided to get an elbow nipple and install it to the existing nipple with a piece of hose...

Better safe than sorry.

Thanks for the heads up. Will keep the oil cooler in place

 

Be careful. If you have EGR running, you will want that coolant flowing through the TB. It is my understanding that it's there to keep the TB from getting too hot from the EGR being injected there.

 

Although I removed the EGR, for clarity’s sake for other readers, the EGR doesn’t go through the TB. It is connected directly to the intake manifold and the only relation to the TB is the vacuum hose going to the EGR solenoid.

 

Early TPI cars have the triangular port between the throttle bores in the plenum, that connects to the runner, which then goes to the EGR system. Later TPI cars don't have it. Pretty sure the cut-off year was 89 when they redesigned the plenum. Regardless many people have deleted the coolant flow through the TB and haven't reported a problem.

The TPI cars after the deletion of the third port still use the TB coolant passage, which would be unneeded if it were for EGR. LIkewise, the V6 has the EGR plumbed into the side of the plenum behind the throttlebody and still has coolant routed through the TB. Evidence points toward being a crutch for prevention of ice on the throttle blades.

 

Ok didn’t know that the middle triangular port went into the EGR via the runners. Thanks for the info and @Tootie Pang excuse me for my remark.

As I said my EGR has been blocked off so no issues on this.

 

No worries! Those GM engineers were always making improvements.

Drew, according to the manual, you are correct. If the coolant is for de-icing, then there is no downside to bypassing the TB in non-freezing climates I would suppose.

 

So after bypassing heater core and TPI TB taking care of tidily buying hoses and bends to look nice I discovered another leak which i couldn’t figure out where it was coming from. After detailed inspection I saw a tear of water coming from under the powder coat of the oil cooler lines!! The irony is I went through all the hassle of routing hoses to accommodate the friggin oil cooler and now it gives up on me...

I need some opinions at this point.
- Do i try to source new cooler lines? Couldn’t find it on rockoil, hawks want $95 excluding shipping (double the price for shipping to here).
- To be honest I am afraid that the sandwich being probably same age will give up and it might mix coolant in the oil!! Can’t find new sandwich for now.
- Do i bypass the whole thing? Throwing away all the hoses and routing the inlet bypass to the radiator or directly to the pump bypass, blocking the radiator?
- If I delete the oil cooler do i remove the sandwich and put the filter directly to the block?

Can someone chime in with some reasonable opinions?

 

IMHO I would just get rid of it all and screw the filter to the block. I just can't see it helping much. I have no hard data but if you car runs around 210-220 degrees how hoes that help to cool oil? Oil runs about 250 degrees (I could be off on this temp) but to me that would not help much. My buddy has that option on his car and mine does not. Both of our cars perform well with and without it. I think I would spend the money on a actual oil cooler, radiator style, than try to replace that system.

 

This is the kind of information I need. You can compare between your experience and your friend’s. Keep this kind of opinions coming !!!! If I were to remove it, is it better routing the inlet bypass coolant to the pump’s top port (currently blocked) or should I use the radiator bypass inlet same one as it is now?

 

I would use the radiator bypass inlet. If you are removing everything just run the radiator bypass hose that comes from the intake base directly to the bypass inlet on the radiator. Besides the upper and lower rad hoses this should be the only other hose needed, this will also bypass the coolant going through the TB. This will for surely clean up the hoses in your engine bay

 

TB has already been bypassed and if I used the top water pump port it would be even cleaner... so if they both serve the same purpose I would simply block off the radiator inlet and install a fitting on the water pump

 

Yep that will work...and look even better

 

Assuming I go down the route of eliminating the stock oil cooler / heat exchanger, and assessing the need for a proper oil cooler, are these Hayden Light, Medium or Heavy duty kits from Rock Auto any good? Where do you guys normally install these on a TransAM? In the Air Dam? Between the Engine and the Fan? These cost very close to a replacement set of pipes for the stock heat exchanger thats why I am considering this option if needed at all.

 

Remove the filter, unscrew the adapter from the oil cooler, replace the two bolts that retain the oil filter adapter with regular bolts, and it's the same as any SBC without a cooler.

Could try sealing the hole in the pipe with JBWeld or whatever metal filled epoxy you like, but if the pipe rusted out in one spot, it's probably compromised in others.

 

Thanks Drew. I already removed the pipes and will reroute hoses however I will still go to the radiator return not to the pump as apparently going to the pump will mean having some coolant bypass the radiator and thus not being cooled.

Any opinions re those Hayden coolers at rockauto?

 

Pretty sure the aftermarket coolers are oil to air coolers, instead of oil to water. You'd have oil pumping all the way up in front of the radiator and back again. I wouldn't think it'd really be necessary on a street car.

 

Yes it is an air to oil cooler. Will try it out without it and see what difference in coolant temp i get. Don’t have an oil temperature gauge so it will be pretty a blind decision though as I don’t think coolant temp will be affected.

 

Yesterday I went to try the car for the first time after bypassing heater core, tb and oil cooler and I can say that somehow the cooling fan was not running for most of the time. Most probably due to the oil cooler not using radiator coolant thus not heating it up and perhaps also due to colder air in the combustion.

Engine is obviously a lot tidier and will post pics once i sort out proper spark plug wire routing.

I am still tempted on an air to oil cooler as cooler water doesn't mean cool oil. I cut some carton dummy shapes of the hayden coolers and cant find a decent place for the radiator. I also found only 1x photo of a 3rd gen on the net with an oil cooler installed and he had the whole front nose removed so it was easier to install in front of the rad.

Anyone has some ideas of alternative placement? Does it necessarily need to be facing airflow to have any effect at all? What about these kits with electric fans?

 

Bump...

Some brand recommendations? Most i can find are chinese..