VR Auto Problems....

[holdenboy]

OK guys ive come across this problem with my VR V6 auto (288,000kms). Nearly everytime i get stuck in traffic on a hot day (thermo cutting in and out a few times) and i go to take off from a set of lights etc, the trans is still in top gear.....it didnt change down into first. When i manually select first gear she goes into first and pulls away, i put it straight back into drive and all is good......with the hot weather recently (well, only high 20s) she's been doing it fairly often.
I checked the trans fluid and it was abit low, so i topped it up and still the same problem.
Transmission was serviced about 40,000km ago, maybe just due for a service?
The auto works fine in cooler weather or when i dont get stuck in traffic etc. Im thinking it may be an option to go with an external transmission cooler, as it seems to be heat related?
Also, one other question....if / when i fit the new cooler, do i have to add more trans. fluid to allow for the extra capacity for the cooler?

Any help is appreciated, cheers.

[hako]

It sounds like the car is going to Limp Home Mode (LHM) meaning the car starts in 3rd gear. This should log a fault code which may indicate a solenoid fault. Check it using these instructions: Checking error codes VR/VS (Revised)
At your miles I'd be thinking it's time for a reco trans unless it's already been done. The external cooler is really only required if your driving is not normal...towing etc. and if you fitted one you would have to add some extra fluid...maybe 500ml.

[holdenboy]

Ahh ok thanks hako.....its just strange it only does it when its hot and i get stuck in traffic etc.
I havent yet looked to see if its spitting out any codes so i will do tomorrow morning. I bought the car with around 245k on the clock so it may have been done before that, it did have a hayman reece power brake assist thingy fitted so i assume the previous owner did some towing, but did not fit a trans cooler.

We'll see what happens, thanks again.

[holdenboy]

OK well just went outside and checked the fault codes, i get a 68 - transmission component slipping?

The check engine light has never come (as far as i know -im the only driver) and generally the transmission is fine

[hako]

Probably not good as it usually indicates clutches are slipping - the code 68 would put you into LHM temporarily I think. My guess is that it will get worse and the only real fix is a reco at about $2000 fitted.
You could buy some time by adding a can of transmission treatment, Lucas seems to be popular - this will make the clutches grip better (they are probably slipping when hot as the oil gets thinner). Treat it gently and it may last a bit more. A service ($150-200) may slightly improve things but the transmission place will probably recommend you fit a reco so really you may be throwing money away.

[holdenboy]

Ahh, ok when i read the "transmission component slipping part" i thought, yep...time for a new one (or manual haha).
So if they are slipping when the oil gets hotter and thinner, would it prolong / reduce the problem if i was to fit a transmission cooler? effectively lowering the trans fluid temp and *maybe* avoiding the temperature in which this happens?
Its only happened a total of 4 times in two years, its only that its done it twice now in the same number of weeks.

I may just try an additive and see how it goes...i should be able to service it myself, would the fact its been 40,000kms since the last service be a factor?

[hako]

The time interval since the last service seems a bit long although some cars go 200,000km without a service. If the oil is still bright red/pink then it is OK but if brownish then it certainly needs changing. Darker than brown indicates severe overheating. A trans cooler I reckon would not achieve much if the car is being used for 'normal' driving......it may lower the temp a few degrees but there is no real proof that high temperatures are the cause of the slippage. It is the actual 'silppage' that is causing the oil to heat up and a cooler will not stop this as it is wear. Transmission additives (fix in a can) are supposed to thicken the trans oil and make it more "grippy".....this way they make clutches and bands grip which are worn and slipping.
What I would do is give the car a trans service - oil ($28) and filter change ($30) then add a can of treatment (go for the dearer stuff...$18) and then treat the car like any other that is 15 years old.
That's under $80. In a year or two if treated gently the trans may last - you probably will trade on a later model.
But if you plan on keeping the car for a few years plus want to make long trips then the $2000 for a reco may be justified. The other alternative is to do the service etc as above to prolong the life of the trans and keep your eye open for a good 2nd hand VR auto - these will be less than $500 and you can change it on a weekend with a mate.

[holdenboy]

Thanks alot hako, ive resetted the ECU and added some trans additive, seems alot better now.....just drove ~200kms without missing a beat, after doing some searching around my radiator etc i found she does have a trans cooler already, its just fitted in between the radiator and condensor for some reason
I'll give the trans a service myself and have a good look at the oil etc, ive done it before and its not the cleanest of jobs, but then again....most jobs involving cars arent exactly clean.

This car is my "work" car (i do car stereo / alarm installations - mobile) so i only baby her around, she's carrying over 300kg of subwoofers / box / batteries so im kinda always towing Seriously, in the two years ive had it ive never put my foot to the floor, im more concerned about fuel economy than being a hoon (those days are over for me, the police helped on that one!)
I realise its starting to get on in life, and soon will need a few grand spent....just want it to last another year or so before i upgrade to a VT/VX wagon.

Thanks alot, your help is appreciated.

[chrisdoesitbetter]

i was reading somewhere about this guy using a three cooler trans setup, he claims it worked well. hako gots his stuff down pat and is always spot on the money and id go with what he said, but i would offer you this advice, dont go to a mech for the fluid change or the trans replacement! its honestly pretty easy and when the time comes people on here will be more than happy to help you out...didnt you give me a guide to installing a cd deck?? :P

[holdenboy]

LOL, yeah i probably did....car audio and generally auto electrics are my speciality. But when it comes to mechanical stuff im abit clueless. Yeah i'll be doing the service myself, i dont think the trans is stuffed as its fine 99% of the time. I read somewhere else this code 68 - transmission component slipping problem can give false outputs and trips the ECU into limp home mode, it dosent worry me that much because i can always just manually shift into 1st gear and she changes normally. Just wasnt sure whether it was a huge problem or it wasa sign of something else, if it starts doing it everytime i drive the car thats when i look at upgrading (or going manual) as i'll know where the problem lies