One for the LSx guys on here

[stumps.]

Post Transmission cooler install issue.

I installed a transmission cooler into my vx ss on the weekend, I installed it in such a way that in runs in series with the intake cooler. The flow goes Gearbox, Radiator, Cooler, Gearbox. I ran the cooler lines over the radiator panel and down through the MCAI to hoses. I added an additional 400 - 500mls of trans fluid to compensate for the lines and the cooler this took the level to about .5cm above the full hot mark when in park and running.

Since the install i drove it from Mandurah back to Perth and initially all seemed well. However i noticed when i "decelerate coast" to a traffic light or an intersection it will constantly change gears like maybe 5 or 6 times over 100m. (4 speed auto). Also the resting idle is up around 960rpm rather than the 860 it was prior to the install. Once putting it in park after a long drive the idle will sit at the above mentioned 960, if you give the throttle a stab up to 3k after release the revs will go down to 1200rpm for 2-5seconds then back to high 900rpm.

I know this is a small issue and does not complete affect how my car runs but it isn’t how it was.

It has a maffless tune so i did a cpu re learn however this did not affect it greatly.

My thoughts are to drain the excess fluid out (I have been told this shouldnt be an issue as it is only marginally above the full mark).

The other thought is that i had this morning because I have run the cooler pipes over the rad support panel this has now become the highest point in the transmission fluid system which is causing any air in the system to be trapped there rather than be released through the previously highest spot the dipstick.

The car was running completely normal before putting it on the hoist, spent a couple of hours doing oil change, oil filter change, fuel filter change, air panel clean and the trans cooler install. Drove out with this issue.

Any thoughts??

[stumps.]

After playing around last night im starting to think it is a sensor, does anyone know which one might do this sort of thing?

[RICEY]

Shouldnt a transmission cooler have auto trans fluid going through it?

Edit: Confused me when you said you added rad fluid..

Id bypass the radiator altogther and go box to cooler to box. Having it go through both may be causing a restriction in the flow.

[stumps.]

cheers ricey, the trans cooler is hooked up as per instructions and as many have before. If you bypass the radiator you miss the radiators fan when you are in stand still traffic causing extra heat.

I have spoken to Mitch at WAperf and he says it sounds like a vacuum leak causing an increase in idle air flow.

I also serviced my oil catch can with new gaskets (neglected to mention in the first post as it seemed irrelevant). So i will disconnect that tonight and see if it makes a difference.

[xr06t]

perhaps a slight pressure drop too with the restricted flow of 2 coolers.

[stumps.]

perhaps a slight pressure drop too with the restricted flow of 2 coolers.

It does it when both completely cold and at operating temperature exactly the same. As pressure changes between hot and cold it would be different in both situations.

Many people have installed these before (PWR for LS1) without issue.

[gav]

yeaH sounds like either a restriction if bonnet closed is squashing hoses, or airating the trans by having the hoses run that high. they run down low for a reason... re route it...

[joshg123]

Most external coolers will ask you to run it in series with the stock cooler, ive hooked them up this way no problems

I personally rather hooking them up seperate from the radiator, as if the rad core breaks at least you dont have the trans fluid in radiator/coolant in trans ive seen alot of my customers stuck with. Havent seen it on a holden box though, but cant hurt to be safe while your doing it.

Dont really understand what your experiencing, sounds like the transmission is locking up gears or is in some sort of limp mode, dont know how youve achieved this, id just be checking for kinked lines.

[stumps.]

Problem solvered, i sent an email to Mitch at WAperf and he said it sounds like a vacuum issue. I took my cheap ass catch can out and hooked the vacumm lines up factory and instantly fixed.

Mitch knows his stuff to diagnose a problem via email.