AWD Transmission: 2006 XC70 Trans blown up issue? Also engine fire

[06d123]

Hello everyone,

I have got an interesting one for all of you...

Unfortunately this is kind of a long story but I feel its necessary to explain it fully incase it might help me fix the vehicle now.

Buying the Car:

First some back story : I bought a 2006 Volvo XC70 D5 AWD with 116K miles around a year ago - the seller was not very forthcoming about the problems the car had and at the time I was unaware of these common issues with the XC70. Long story short, the engine needed swirl flaps and the gearbox had a clunk between 3rd and 4th. I had the swirl flaps and also the timing belt replaced as these were quite important items. The car was very drivable and I put about 5k miles on it with the trans clunk. But, I was unhappy with this as a long term solution as the idea of one bad shift blowing up the trans, leaving me stranded at the side of the road - was not very appealing. So I got a used transmission from a salvage yard and had it installed, it was kind of a gamble as I did not know the condition of the transmission I was installing, but it appeared to have paid off as after the install - it was shifting beautifully through all the gears.

The Dealership:

Around 5k miles after the trans install, I was driving one day - car was perfectly fine for hours - pulled into a service station - then upon leaving the service station the car had no power. No errors on dash, no lights, would not clear by cycling the ignition - the engine was extremely slow to rev and pretty much undriveable. As I was away for work, I didnt really have any other choice but to take it to a main Volvo dealer and see what they could do. Outside the dealership I had a look at the engine and noticed that the swirl flap actuator was not moving when the ignition was cycled, It always seems to do this calibration in and out movement but it appeared to be stuck. It was late in the evening at this stage so the dealer agreed to look at the car the next morning - so I limped it to the hotel. The next morning, I got into the car and there was no more issue, car had loads of power and was perfect. When I got to the dealer I checked the swirl flap actuator and it was moving this time (so you would assume as I did, must be a bad swirl motor right?)
The dealer scanned the car and told me that I was going to be stuck here for awhile... It was coming back with codes for swirl flaps on different cylinders jammed and something to do with the EGR. I couldn't understand how the swirl flaps could be jammed as I had these replaced by my local dealer only a few months ago. There was also a code for a malfunction with the swirl flap motor so I suggested that maybe just the motor was faulty? But no, the dealership insisted that if I was to drive the car with these codes, there was a 99% chance the engine would blow up, they were insistent that it was either a faulty part or bad workmanship from the last dealer (this is kind of ironic because of what happens later in the story) .

So.. I didnt really have a choice but to leave the car with them so they could replace the EGR and investigate the swirl flaps.

About a week later they got onto me to say that the car was ready, I was delighted to hear this as the courtesy car (Seat Alhambra).. although fun to drive a mom wagon.. was not really doing it for me and I really wanted my Volvo back. Upon going into the dealership, I was presented with a bill for over 1.6K for the replacement of the EGR and they told me that all the hours they spent disassembling the engine to inspect the swirl flaps was futile as there was no issue - so it turned out to be the swirl motor 🤦*♂️
The dealer knew the had messed up, so the main service manager I was dealing with the whole time along was conveniently "busy" when I came in that morning. After some back and forth I got them to remove all the unnecessary labor from the bill for accessing the perfectly working swirl flaps, this brought it down to about 900ish, so I decided to just pay it and chalk the rest down to experience. At least I could finally enjoy my car again! right??...

The Fire:

I left to dealer to head back home, happy to finally be back in my car. It was a kind of wet/misty day so there was a lot of spray from the motorway, as I was driving down to motor way (on the passing lane) - somebody pulls out right in front of me - turns on their hazard lights and brakes. I had no idea what they were doing. I couldn't tell if my car was smoking or something as there was all the spray from the wet road. I assumed that maybe the new EGR would maybe smoke a bit as it got up to temperature or something? maybe the dealer had installed it wrong? I decided to pull into a service station just off the motorway - about 15 seconds after the guy had braked in front of me. I slowly pull into the car park... find a nice parking space.. but then, the second I stopped the car I could see smoke pouring out from under the bonnet. I quickly jumped out and opened it and.... yeah, the b**ch was on fire. Ran into the McDonalds in the service station and grabbed all three of their fire extinguishers - AND - it took ALL THREE of them to put out the fire.
So I called the dealership to tell them what had happened, my car had just burst into flames 5 minutes down the road from the main dealer. Id say the poor service woman almost had a heart attack when I told her what had happened. There is a big long story to be told here about how the dealer made this right with me but at the end of the day, I just wanted my car put back to the way it was before all this happened, so they agreed to fix the car. About a month later (I was given a brand new Volvo S90 as the courtesy car this time) the poor old XC70 was ready to be collected. It cost the dealer about 10K to fix the car and they had to buy a second XC70 for parts as some of the plastic pieces (scuttle, engine cover etc) could not be sourced new. The car was working perfectly now and I was delighted to be back in it. At this point it had about 130K miles.

The Unfortunate End (or maybe not?):

On February this year, I got into the car like any other morning. Drove it all day and it was great, I had only commented in the morning about how well it had been working. The car now had about 137K miles. On my way back home, I was on the motorway. It felt kind of funny, I was trying to keep pace with traffic and I felt that I had to put my foot down more than usual in order to keep up. I let off and cruised instead of passing everyone like usual, I then got a warning message on the dash saying "Transmission temp high" - This was just before a toll booth so I started slowing down to go through the auto toll lane. As the car down shifted it was flaring and clunking the gears. When I tried to speed up again (the car was only going about 15mph at this stage) the engine would rev but there would be almost no movement. I then also got an error for "Transmission performance low". I pulled in just after the tolls (not like I had a choice, the car was not moving!) Called Volvo break down assist, towed to a dealer, got a taxi home. The dealer called next day to tell me that it was outputting code TCM-012D Gear Shift Function Wrong gearratio - this was apparently some kind of internal fault and they said the car would need a new gearbox...
I still had to get the car home, so I went into the dealership and organised a tow truck. I had to move the car out onto the road as the truck would not be able to pick it up from the parking spot in the service department. The car started fine, and it engaged drive enough for me to be able to pull it out onto the road. Got the car delivered home and parked it in its current resting place to this day.

My Diagnosis:

So, needless to say, I bought another car... with my previous experience with this car can you guess what I bought? something sensible like a Toyota or a Seat Alhambra maybe? Hah! I bought ANOTHER XC70 BABY! This time in black with pretty much the same spec (the big difference is that this one was properly maintained and I knew what to look out for). These are fantastic cars, last of the true Volvos, and I need your guys help to fix my poor old blue XC70. I bought a VIDA diagnostic laptop as I'm kind of a slave to Volvos at this point. I also still have the old transmission that originally came with the car with the clunks FYI.

I drained the transmission oil and it looks fine, nothing out of the ordinary in my opinion, no metal fragments, the oil was still slightly red and still had an oily texture. I just filled it back up again with the same amount I took out (still no drive, kind of moves in reverse). The error code TCM-012D still exists, I can clear it - then if I put the car into D and rev it (no drive ofcourse) it pops up with the error again.

The Weird things:

Ever since I got the car back home after its motorway blow up - when I run the engine (it runs great) - there is the most awful smell coming from the exhaust. I don't know how to describe it - it kind of burns your eyes and nostrils. I read that this is apparently what a diesel engine smells like when the DPF is doing a regen. I got no message on the dash or anything to tell me that the car was performing any regen and the VIDA doesn't seem to pick up any codes for it (maybe I'm not looking in the right area)

My Theories:

1. The replacement gearbox could have had 200K+ miles - The transmission had a slight leak so possibly the level got too low - the fluid got overworked and overheated - in turn it cooked the transmission.

2. (this one is kind of out there so please bare with me) Ever since I got the car back since the fire, it was getting worse fuel economy, not by much - its average went from around 34MPG to about 30MPG (measured from full to empty tanks) - When I removed the air box to drain the transmission oil - The clamp on the air intake hose just after the MAF was loose - so maybe this air leak caused the engine to run slightly worse - this then has clogged the DPF over the 7K miles I did. The DPF is next to the transmission - maybe the DPF got hot and cooked the transmission?

3. The speed sensors in the transmission, clutches, solenoids or the TCM itself have gone bad and took the transmission with it.

4. The dealership missed a wire/sensor when rebuilding the car. This could be why the DPF seems to be clogged and I got no notification of any regen.

All I really want to do is fix the car, I just need to figure out what caused the problem/ what could be the problem. So far it seems to be an internal transmission fault but since the car was working so well I don't understand why it would just let loose? The smell from the exhaust must also have something to do with the issue. I don't think I can do a regen as the car is not drivable - and there is no point in fixing the transmission if it was another issue that caused it to blow up in the first place.

PS : When I got the car back from the dealer - I drained the fluid - I got about 4.5 litres out of it.
I put back around 5 litres of fresh fluid - brought the car up to temp - incorrectly opened the fluid level plug without putting the car through the gears - 2 litres came out (more would have drained out but I knew I had done it wrong so I put the plug back on while it was pouring out)

I then poured 2 more litres of fresh fluid and put it back in again to correct my mistake - haven't set the level since that point - car still has no drive.

So realistically - the car drained out 4.5 - I put back in 5 - still no drive.

Thank you very much if you actually read all this, hopefully it all makes sense. I look forward to any suggestions you might have to help!