ATF level

[Nick Mann]

This is a new one on me - anyone else care to comment?

A nice couple new to VR4 ownership popped over to see me on friday, just really for a cup of tea and a chat about their new VR4. Following a quick test drive I suggested that we check the gearbox ATF - the changes were harsher than ideal and I commented that the oil could be incorrect/wrong level/old.

On parking up and checking the fluid (engine running, gearbox in N) there was nothing on the dipstick. Nothing at all! The owners had looked at one point when the car was cold and were convinced it had been showing on the COLD side of the dipstick.

Sure enough, on turning the car off, the oil came up to the COLD level. It was not a nice colour, though!

After a chat, they decided to get me to flush the oil there and then. About 14 litres of Amsoil later, the oil is now ruby red and back on the cold part of the dipstick. We go for a short drive again, and the gearchanges are now spot on. On pulling up and checking the dipstick - there is NOTHING showing again! I decide that the fluid must have settled after the drive, and start adding. It takes another litre to bring the fluid up to the HOT side of the dipstick. We turn the car off. Shortly afterwards, as they are about to leave, we check the dipstick again. The fluid is now over the top of the HOT mark. ???? I decide that the HOT reading is the important one, and suggest that we should go by that, not by the cold reading which seems to be higher than the hot reading in every case.

Over the weekend the car has been spitting out fluid, suggesting to me that it must be over filled. That in turn suggests that the COLD reading is the one that is correct. I have never seen this on a VR4 before. The HOT reading has always been the one I have gone by, and I have never had this issue of the COLD reading being higher than the HOT reading?

I think that I ought to ask the owner to come back and have the level reduced based on the COLD reading, rather than run with a box that is over-filled. But I am worried about why the HOT reading is incorrect?

[elnevio]

Wow! That is an odd one.

So it come up to the COLD marking once it was turned off (but still hot). Was that in P or N? It still suggests that it is coming up to the COLD mark when off, regardless of whether the fluid is hot or cold, which is also odd.

Is it possible that a solenoid (or something that controls fluid flow) is operating incorrectly, or not at all, while the gearbox is in N?

[Nick Mann]

Fluid measured hot with the engine running and gearbox in N.
Fluid measured cold with the engine off and gearbox in P.
Approx 5 minutes after turning off engine before fluid level checked.

[miller]

Its not something silly like a shorter dipstick, ie a FL dipstick in a PFL?

Guessing! Though why they would be different lengths is another story

[Nick Mann]

Not that I could see. But the hot measurement should be higher than the cold measurement. That's why the dipstick shows HOT above COLD. :P

This car seems to show a higher level when cold than hot, and it seems that using the HOT level when filling it up results in an overfilled box.

I don't understand why, so I am struggling to give the owner good advice.

[Mark 4]

Is there an oil cooler fitted that is above the fluid level ?

If so then when the engine is running it will be full of oil. Switch the engine off and that oil drains back down.

Just a guess.

[Nick Mann]

No oil cooler. Good idea though!

/edit - no additional cooler - factory radiator jobby still there.

[elnevio]

Along these lines, has the standard cooler been disconnected, or reversed, or blocked? I wonder if that could have an effect on oil level.

[Nick Mann]

Whe I flushed the fluid, I flushed the cooler through. No issues there that I could see. The oil flushed through at a normal rate. That would imply the feed from the pump through the assorted gubbins including the cooler is all okay too.

[elnevio]

Is the ATF just too thin when it's hot to read on the dipstick? I find it looks like this when reading mine!

[Nick Mann]

Nope. The dipstick is completely dry in areas the oil hasn't touched.

[elnevio]

Then back to my suggestion of a dodgy solenoid when in Neutral, send the flow the wrong way, or something. Although that would suggest that you'd still get fluid on the dipstick, although cleaning it off then trying to check it again would come up dry, so the dipstick must be dry for quite a while (i.e. when driving and using all the gears), yes?

Aargh! A right head-scratcher this!

[Turbo_Steve]

I would hazard a guess that one of the filters is a bit clogged, so that the fluid is all being pulled into the hydraulics on use, and then as soon as the pump stops it all flows back into the resevoir.

Either way, I'm not sure it's ideal. The big question would be, I guess, where is it spitting the ATF from?

[Nick Mann]

I don't yet know where the fluid is being spat from. I am told that the level of spitting is reducing as time goes on. The car will make another short journey tonight and the owner will check the fluid levels again, cold and hot, and this time in P as well as N.

[Davezj]

This is bit of background to my thought process
"i know when i had an auto jeep and i was an auto virgin, i did not realise that the hot level was to be measured after cycling through the gears, i found that the hot level was way to high (or so i thought) so i emptied out about 1L of ATF which brought the hot level back to the hot mark on the dipstick.
then when the auto box was cold i checked it again and it didn't even regiter on the bottom of the dip stick.
i topped up the ATF to the cold mark and now realising my mistake got the box hot and check the level. it was way to high, then cycled through the gears and hey presto the correct level."

This is just a thought and please correct me if i am wrong here, but i will have a go explaining a theory.
when the ATF is hot it has expanded and fills a larger volume within the Auto box so the level appears higher. when the gears are cycled, the gear box fills up all the relevant solenoids and oil ways within the auto box ready for changing gear again(pressurises the box, if you like), which reduces the ATF level to the correct monitoring point but is still higher than the cold level.
when the ATF is cold the ATF shrinks and has a lower volume takes up less space in the auto box, but it drains out of all the oil ways and solenoids.

and to get to my point,
when the level was checked for cold was the ATF really cold, or was it still hot (expanded volume) and drained out of oil ways/solenoids giving an artificially high cold level.

so when the gears where cycled through, the oil ways and solenoids filled up and dropped the level of hot oil. to below the hot "cold" level.

so the hot level was being measured against an artificially high cold level.

as for the spitting, it may just be one of the hoses to the trans cooler in the rad that is not quite clipped up and is a bit of a red herring (unless it is coming from the dip stick itself then it would suggest over fill).

would this explain the situation.

[steelie600]

I fully concurr with Dave here, theory is sound and was gonna be my answer but i cant put owt as elequently as that.

[Nick Mann]

I can't see it, Dave. If the dipstick reads right on the cold level (Seems to be about the same when cold and when hot but engine off) then the dipstick reads nothing oce the box is hot, engine running in N.

[steelie600]

Nick, could it be that the level needs to be checked with the engine off??

I know most auto boxes require the engine to be running, but is it possible that the engine needs to be off on the vr4??

[Davezj]

the whole crux of the possible explanation is the cold level you were reading was not actually cold. it was still hot e.g. the car had been out for a drive and then left for 5 mins the and cold level is checked the ATF is not cold, it is still hot.
and if that level is pointing at the cold mark, the moment you cycle the gearsATF is succed away to fill oil ways and the level drops off the dipstick.

but it this theory revolves around the fact the ATF was not really cold when the old level was checked. the auto box stays hot long after the engine is turned off.

[elnevio]

No Kev, this car is definitely the anomaly!


Nick, I reckon it might be a case of explaining that their car's autobox may have a problem (BTW, I take it there are no stored codes in the gearbox ECU?), as manifested by the incorrect reading level when it should be fine, and that whether this is a real problem that may present itself with other symptoms later on is potentially what may happen, but given that it's loads better than it was, then it's unlikely to cause an issue now or even in the future. But that the only other option would be to dismantle the gearbox to inspect everything inside.

It's a shame that that's a bit of a cop out, but there's no explaining the unexplainable!

[swinks]

Nick, IIRC service manual for Galant n/a says: check on P, not a N. There's difference in fluid level. /Hmmm
"Cold" mark after shifting on idle before run, "hot" mark after run and engine warmed up.

[Nick Mann]

Resource Library
=>Engine stuff
==>Automatic Transmission
===>Workshop manual

Go to page 46. It says something along the lines of:
1. Drive the car to reach normal gearbox operating temp (70-80 degrees).
2. Park the car on level ground.
3. Cycle the gear lever through all gears to ensure the oil ways are all full of oil. (There's more to cycle through on the non-tip box in the Galant, which seems to be what the manual is based on.)
4. Put the lever in position N
5. Check the level and condition of the fluid. The fluid should be on the HOT mark of the dipstick, if not, fill with fluid until this level is reached.

It also mentions that the cold mark is to be used as a guide only and the hot method of checking is the correct procedure.

There is something strange with this gearbox. Trust me - I have seen a lot of them! I just can't work out what is strange and why. I believe I have added the oil as per the instructions in the Mitsy manual and as I have done to countless other VR4's. No other VR4's see the fluid level rise when you turn the engine off.

My doubt is this - with the high cold reading and the spitting of fluid, I am concerned that the oil level is too high. However, I am unwilling to make a recommendation to ignore the Mitsubishi workshop manual and my experience and just take fluid out so it stops spitting. The owner is obviously confused too and I can't answer his queries. The car has been driven and checked again tonight - the hot reading is still spot on. The car was checked stone cold before it was moved and the level appeared to be way too high.

The only thing that sounds plausable now is a partially blocked internal filter. (The box doesn't have an external filter.) This could maybe be preventing full flow back in to the sump, but keeping pressure in important bits to allow the box to function correctly. This obviously is not a cheap thing to check or sort out!

[Davezj]

that is fair enough nick, i know you know what you are talking about when it come to auto boxes and the like you have seen enough in your time.

this is an odd one, the work you have done will not have had any detrimental effect on the auto box,
the only thing i could suggest would that i would be inclined to do almost nothing, just set the ATF level so it does not spert out of anywhere and hopefully at the hot level, then just run it for a few weeks, to see if the amsoil can do any good decruding the insides of the auto box. just keep checking every day, or the owners check it every day. it doesn't take long to check. maybe it will work itself out without the need to strip down the box.

apart from that you can do the solenoid pressure tests on the external bolts on the auto box. but i have only seen this procedure in the 4 speed auto box workshop manual and not in a 5 speed workshop manual.
i can give you a copy of the 4 speed workshop manual if you want it to have a look at, but it is available on the site somewhere.

[Nick Mann]

Aye, Dave it is. It is in the resource library - follow the route in my previous post. I have checked pressures before on my gearbox when it stopped working, but all it did was prove that it wasn't working!!

The owners are checking the fluid level regurlarly and I'm sure they will continue to do so. The box is still changing gear beautifully. If it weren't for the patch of oil on the road where they come to a stop and the huge amount of oil on the dipstick when cold, everyone would be happy!

I posted this thread for two reasons - to pick other peoples brains and to see if anyone else had noticed this issue on a box. Many thanks to all who have suggested stuff! And it seems as though no one has experienced this first hand, so we are still none the wiser.

[Wodjno]

Strange 1 Nick /yes
From reading your 1st post, i was thinking on the same lines as Mark, with an Aftermarket oil cooler somewhere in the loop at a raised level.
You sure there's no added cooler?

[Nick Mann]

I didn't see one. The pipes certainly are all original from the battery area to the radiator. It is possible that the pipes have been re-routed from the wheel arch area through a cooler, but if they have it must be mounted underneath the battery - the area behind the spot was empty, as proved by a gaping hole where the wheel arch liner should be!

I would be suprised if there is a cooler there, But I guess I can't absolutely guarantee there isn't. I'll suggest it to the owner on our next conversation.

[Davezj]

i will keep an eye on this thread to see what the outcome is. Good luck and keep us all posted.