gilow
Hello all,
The reasonably-new-to-me V70XC is turning out to be quite a joy to drive. A few niggles here and there, seem to be having a run of poor contacts in the tail light assemblies at the moment, but otherwise good for a car with 220K on it and making the trip to work each day a little better than it might otherwise be.
We recently did a 1400km trip towing a small trailer which went well, but since the trip I have noticed an odd thing. From time to time there seems to be a bit MORE power than usual. It is totally random and I don't THINK it is a faulty TPS (which I understand are a problem with this car, but mine gets cleaned every service), just from time to time as I pull away from the lights the car seems to have a bit more pickup than I expect. The reason I don't think it is TPS related is that I feel the amount of throttle variation that would be required to produce the extra power would also be enough to kick down the auto and in these cases there has been no gear change.
I do drive the car very gently, given the fragility of the transmission, so I am wondering if there is something being hidden by my light-right boot. If I had to guess I would think it was some kind of system designed to bleed power from the engine, maybe some kind of turbo limiting device, or engine damage prevention system like the old Saab EMS, that is turning off and on intermittently. It has a very faintly turbo-lag feel to it, but not apparently directly related to engine revs as I would expect from turbo lag.
Any suggestions of where I should look for problems?
Matt
timbo
probably a faulty turbo control valve. Its a solenoid on the side of the airbox with 3 vacuum lines going to it. They are a quite common problem
gilow
Thank you, I've just did a bit of searching and reading about theses following your suggestion. The symptoms fit my experience pretty well.
One thing I was not clear on though was if this did apply to my low boost setup? All the discussion, not suprisingly, seemed to be around the R series Volvos, which, if I understand correctly, are the sportier high boost turbos.
Matt
gilow
A year down the track and I just noticed I did not post a follow-up to this one. It did turn out to be the turbo control valve, one of the (three?) hoses to the valve was loose. So anyone searching on similar symptoms might be wise to check the hose connections. All has been perfectly smooth driving since fixing the connection.
bigal
@gilow Hi. Regarding what you said about the fragility of the transmission.. have you had the latest TCM software applied and had the neutral control function disabled? I've read in various places that a major contributer to the aisin tranny problems in the pre 03 xc70's is the neutral control funtion. The flipping between drive and neutral and back again with stop and starts seems to really mess them up over time. Volvo disabled this 03 onwards with the aisins due to this.
I'm no expert, just sharing what I read in quite a few places when researching and deciding between xc70s and 90s.
gilow
Hi bigal, thank you very much for that check list, good of you not to assume I knew about those.
Yes, I can confirm all that has been done. A year down the track I feel a little bit more faith in the car, but I will always drive it gently (more my style anyway) because I fear the transmission will always be the weakness of what is otherwise a very nice car to own and drive.
Ex850R
Be proactive on the gearbox , have it sen by a independant volvo tech ( ask here ) , have it flushed and the software updated. It WILL save a good box BUT it wont fix one thats going / failing.
gilow
Thanks Snoopy, good point. It has been done. My Volvo mechanic is all over the software issue, he installed his preferred version when he put the gearbox in the car, and I asked him to do a flush of the gearbox on the first couple of services just to be sure. I think he was torn between what he knew it would cost me vs the feeling that it wouldn't hurt and might certainly help. But it was my money so after giving the pro and con arguments he went and did as I asked. So I think it got three flushes once it was installed in the car. Now we will do a slightly increased frequency oil change on the gearbox. Can't remember what the interval normally is, but I suggested we routinely do the flush one or two services ahead of normal schedule.
The only thing that worried me about the gearbox initially is that on VERY cold mornings it seemed quite reluctant to change up a gear, but I read something in the manual about that being by design and something to do with the oil viscosity and not damaging something else. Goodness knows what, but it has been that way since I bought the car and the gear changes are fine on all but the coldest mornings. On those mornings it takes about 1 km before the gear changes become "normal" again. I just take it slowly and let the car sort out when it wants to change gears.
jaykenneally
Hey mate, Snoopy is right, keeping these autos reasonably happy is all about being proactive and not waiting until it goes bang.
I think the Volvo schedule is every 75,000 kilometres. Most transmission companies and fluid companies design for 50,000 kilometre intervals. I recommend mum do hers every 30,000. We have flushed out mums auto fluid to be a silky red colour again, and now every 30,000 all we do is drop the oil and fill it again, 4 litres will do, costs 50 bucks. Every 100,000 or so I'll probably tell her to completely flush it red again. Its probably over kill but I don't care, mum tows alot with it so its better to be safe than sorry. Hers however is a 2006 model with the slightly improved auto.
Sounds like you have the same ideals about spending a bit extra and staying on the safe side which is good. As I say Volvo recommend every 75 k so if you want to be proactive do it ever 50 k. You could also do it say every major service or every 3rd service (if you do it at 15k intervals) or every 6th (7.5k intervals).
The gearbox having a reluctancy to change gear IS normal and will be noticeable in the cold. It is a feature designed to warm up both the engine and transmission faster. Shifting might also be rougher in the cold until it warms up, so don't stress too much about that :)
Ex850R
As an example , the missus Camry doesn't change up wnen cold as does my V70 98 at times.
