vs automatic trans 'thud' over 80k's + cooling issues

[SweetWagon]

Hey guys,
Recently purchased a VS Wagon (auto ) Been having a problem when cruising over 80kmph, and then accelerating to overtake or up hill, there appears to be very noticeable thuds or knocking in quick succession coming from the auto until it either kicks back a gear or i manually pull it back/back off. So it seems it only does it when the torque converter is locked up it tries to keep disengaging/re-engage till it makes its mind up? Is this a common problem with the auto? should i worry about fixing incase it fails as i plan to drop a manual in it very soon just need a flywheel to suit a t5 on the ecotec i already have all the other parts. transmission fluid level is fine.

Also while im here It also has a cooling issue, cruising residential area's (ie. stop/start at low speeds) the temp will often rise to 3/4 and but slowly falls back to half when stopped at idle and goes back to 1/4 (normal) at highway speeds. It had very dirty rusty water when i got it but it has been flushed once and replaced with new coolant, new rad cap and bled. I checked thermofan is working and thermostat has been checked which we suspected to be dodgy so Its been 'modified' ie. (partially removed) incase it was seizing, which ill replace with a new one this weekend, but still getting very hot so could a blocked radiator be the culprit?

Cheers!

[hako]

3/4 is the point at which my fans turn on so I wouldn't be too worried about that unless the car is actually boiling. It will cycle from 1/4 to 3/4 in slow stop/start driving and most other VS models behave this way (there are exceptions). Re the trans....sound like the torque converter clutch slipping/sticking - how long it lasts is anyones guess but I wouldn't be doing long trips. Maybe throw a can of Lucas trans treatment in....might hold off the inevitable.

[SweetWagon]

3/4 is the point at which my fans turn on so I wouldn't be too worried about that unless the car is actually boiling. It will cycle from 1/4 to 3/4 in slow stop/start driving and most other VS models behave this way (there are exceptions). Re the trans....sound like the torque converter clutch slipping/sticking - how long it lasts is anyones guess but I wouldn't be doing long trips. Maybe throw a can of Lucas trans treatment in....might hold off the inevitable.

Thanks hako, i wouldnt think 3/4 is considered normal? on my past vn's the thermo would kick in at halfway and never/rarely climb above that point.. also i noticed the vs has a two speed fan how can i check low speed is working?
I think you may be right about the auto, it seems very smooth and firm apart from that, i want to keep it another few months yet, i travel from sydney to canberra twice a month so dont want it breaking down, would a new filter and that trans treatment you mentioned be worthwhile?

I think i'll remove the rad on the weekend and do a full reverse flush when im replacing the thermostat, atleast then i have peace of mind that it isnt blocked (old water was fairly filthy) as previous owner didnt use coolant in it.

Also i have a 2-3" round flat plated section in the front/middle of the sump that looks like its been welded in, is the normal or has the sump been patched/welded up?

[Brett_jjj]

You can test the radiator fan speeds.Disconnect the temp sensor wiring from the sensor,Thats the temp sensor wiring connector with the plug near the thermostat cover,not the single wire gauge one near it.Start the engine,then after around 12 seconds the fan should start on slow speed.Then after a further 6 seconds the fan should switch to hi speed.If it does this its working fine.

[hako]

You can test the cooling fan by removing the connector from the coolant temperature sensor then starting the engine (cold) - after 12 secs the fan should start at low speed and then after 6 secs it should go to Hi speed.
The VS with the Ecotec engine runs hotter than the Buicks - due to increased efficiency etc. I'd also do a filter and oil change on the trans and the treatment...should cost about $50.
From memory my sump has that same welded patch....not sure if it is actually welded or if it was part of the casting mould.

[SweetWagon]

You can test the cooling fan by removing the connector from the coolant temperature sensor then starting the engine (cold) - after 12 secs the fan should start at low speed and then after 6 secs it should go to Hi speed.
The VS with the Ecotec engine runs hotter than the Buicks - due to increased efficiency etc. I'd also do a filter and oil change on the trans and the treatment...should cost about $50.
From memory my sump has that same welded patch....not sure if it is actually welded or if it was part of the casting mould.

Ok good to know guys will try that test on the cooling fan on the weekend. The temperature is very fluctuating and it liked to dump coolant from the overflow on the ground after the car was parked and turned off. hoping the new cap fixes this. The bleeder valve on the thermostat was completely blocked so this also leads me to a blocked radiator. trans oil looks very clean i might even just add that treatment to temp fix it till the manual goes in.

Was a bit worried that the sump had been repaired/welded up thanks for clearing that up hako.

[wackywheelz]

The auto if unable to lock the TCC (Torque Convertor Clutch) should throw up at code @ roughly 100kmh. Lots of things can cause the TCC to go poopies, it is usually bought on by grit smaller than the filter can trap.

[SweetWagon]

The auto if unable to lock the TCC (Torque Convertor Clutch) should throw up at code @ roughly 100kmh. Lots of things can cause the TCC to go poopies, it is usually bought on by grit smaller than the filter can trap.

I will check error codes tomorrow when i service the trans (bought a service kit + new ATF). Its def a slipping TCC under load and If i have to replace the converter I have to pull the trans out anyway thats why i'm holding it off a while until i can afford a new flywheel and clutch for the manual. I can almost predict when it will start shuddering so im going to try pulling it back to 3rd under load to reduce further wear on the TCC. If it does crap itself though would it lose drive altogether?

[SweetWagon]

Quick thought.. would cutting the wire for the TCC stop it from engaging therfore preventing any more damage to it. sure it will throw up error code and a bit worse on fuel on the motorway but im willing to live with that for a while. thoughts?

[SweetWagon]

Trans out tonight, those cooler lines are a royal pain in the ass! ended up cutting them, got some hose to patch the cut sections, should be fine? Plus makes it easier in future having a flexible section. Picking up the exchange converter tomorrow hopefully fixes the problem, old man reckons they used it for towing a caravan.

Also car boiled on saturday going for a test drive (mind you it was 35+ degree heat) so pulling radiator out tomorrow hopefully and try and unblock all the shit inside!