Hi, I wonder if anyone could offer some advice, This morning the box would not change out of 3rd, i was on the motorway so stopped at the next services, turned off, back on, all seemed ok.
Returning home tonight same thing after approx 40 miles, i stopped again but this time no effect, would not change up from 3rd, tried manual mode, and could see 4 seleted but the box would not move.
Now i'm limping home, i get a "Transmission Overheat" Message.
I stopped again, waited and re-started, now it would not go into 3rd, only 1 & 2.
The Car is a 2002, with 66K, anyone have any idea what could be wrong with the box

Your transmission ECU is trying to protect your transmission from the fluid overheating by inhibiting upshifts to keep the engine speed (& therefore the flow rate from the transmission oil pump) high.

The most common cause is that the bottom eight rows in the main radiator have become blocked with sediment preventing the coolant getting to the transmission oil cooler.

Phil

Hi Phil

Had a recent water leak at the Coolant Manifold, so i used rad weld to get me home (It worked).
I had the repair carried out by an Indy, they also discovered a leak in the radiator, so also changed that.
This was the first journey after the repair, i will get them to check the Rad for blockages first off.
Also the gearbox has been recently re-conditioned, with the Torque converter replaced, it has 10 months warranty remaining.

Thanks for the reply, i will let you know the outcome

If you have one of those cheap digital IR temperature laser guns you could check the temperature of the metal sump pan at normal operating conditions. The fluid should level out at around 100-110 deg.C (similar to the engine coolant). If it’s reaching 130 deg.C + then you have a problem in the cooling circuit. If it’s not the radiator causing it you should suspect the transmission cooler itself next.

Phil

Had the same problem a couple of years ago, the rad weld restricted the flow in the transmission cooler. A new cooler solved the problem.
Stewart

I had similar problems earlier this year, where everything would be fine and without warning it would downshift to third and then second. Despite letting it re-boot repeatedly it kept happening. I sent to a local transmission specialist who drained the oil, took the sump off and removed & cleaned the valve block. He reported to me that the gearbox had insufficient oil in, about half the recommended capacity. since then it has only done this once - this is since July. it sounds very similar to me. I just got back from an auto gearbox specialist having had the current problems (cattle grid judder etc) diagnosed - need a new torque converter etc!! these cars are fantastic, but expensive when they go wrong! best of luck but I would have the oil levels checked at least.

Update:
Coolant level was quite low, so the mechanic thinks there may have been an air lock after the new rad was installed. I will give it a whirl and keep an eye on the gearbox oil temperature.

Problem not solved, oil temp up to 143 Deg C after driving for 20 miles, next stop, oil cooler

New oil cooler fitted, larger than standard, and independant of the engine cooling system.

Drove it for a couple of days, checking the oil temp after each run, of approx 20 miles, temp was around 114 deg for every run, tonight it was up at 131 deg after approx 45 miles including some motorway.

This seems a little high to me, does anyone have any thoughts

You should not have replaced oil cooler without getting the radweld out of the entire system under pressure. Only other solution is to replace Main Radiator, Oil Cooler & all pipes as RADWELD is a to get out. You probably had a partially blocked radiator anyway and the readweld would have just cemented it in.

A New Oil Cooler alone is going to get reblocked pretty quickly and more overheating. I would take to a tranny specialist and get a pressurised flush of the whole system.....

Quote:

New oil cooler fitted, larger than standard, and independent of the engine cooling system.

Thanks for the reply

The radiator was replaced at the same time as the coolant manifold.

I havent inspected it yet, but was told the new oil cooler was larger and independant of the engine cooling system, so i assumed it would be air cooled.

The Oil cooler was fitted by a tranny specialist

So everything (Rad, Pipes, Cooler) was replaced AFTER the Radweld incident?

Sounds to be the Tranny Specialist was ill informed. The last place I talked to also said that the Engine Radiator on the L322 was not linked to the Oil Cooler.....

Idiots need to have a proper look or get a copy of RAVE.....

No Just the rad and the coolant manifold, i will make some calls tomorrow

Someone one one of the forums had the same problem and he changed all of the cooling componants, raditator , oil cooler. He never thought to check the 2 pipes from the transmission to the oil cooler. Eventually he got around to changing these two pipes, and this solved the problem. MY2010 TDV8 Vogue Ipanema Sand
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