Trouble accelerating past 55 mph in 98 V70XC - transmission?

[bubbeck]

Hi everyone,

I was accelerating on the highway from a toll plaza the other day in my 98 Volvo V70XC (205k miles) when I found I lost accelerating power around 2500 RPM and 55 MPH. It felt sort of like the transmission was between gears and wasn't putting power to the wheels. I didn't observe any flashing up arrow or SEW lights like you might expect from limp mode, but I wasn't looking for them at the time.

I was able to drive to the next exit at 55 mph, where I stopped and checked for engine and transmission codes. Nothing for the transmission and only the good ol' P0440 for the engine. Following Robert's guide, I checked the transmission fluid level; it was at the high end of the hot hash marks, and pretty brown in color. I also noticed that the fresh air intake hose had popped off its inlet, and that it was somewhat crushed where it attached to the inlet. It was unclear whether it was like this while I was driving - I might have leaned on it trying to get at the transmission fluid dipstick. I straightened it out and popped it back on the inlet.

Seeing no better alternative, I drove the remaining 150ish miles home on secondary roads. The car seemed to drive just fine - there were some pretty hilly sections and I was able to accelerate normally past 55 mph. The shifting seemed maybe a bit slow, but maybe I was just being sensitive.

Any ideas on what might've caused this and how I might fix it? How worried should I be? Or other tests I should perform? I suppose I should probably at least flush the transmission right, seeing as the fluid wasn't a nice bright red and it probably hasn't been done since at least 150k miles. If it was the intake, any suggestions for keeping the hose on the inlet? It seems like the hose is a bit short and keeps popping off.

Thanks folks!

[scot850]

Check you got all the turbo hoses to the intercooler connected tightly and correctly seated. Also check the small pipes to the TCV for damage or splits. Simple stuff first. Also check you got the pipes connected the correct way around on the top of the oil separator box. It is easy to get them the wrong way around and it seems to cause issues.

I your tranny worked before the PCV work, it should be still ok. Doing a drain and fill 3-4 times is the easiest way to change the fluid without causing issues.

Neil.

[bubbeck]

Yeah I didn't think it was PCV related - I've driven about 5k miles since that job. Would you recommend draining and filling the transmission fluid? Also do you know of a good place to find under the hood diagrams to locate the intercooler/TCV?

[scot850]

The intercooler is sandwiched between the radiator and A/C condenser. It has the large pipe rubber pipe running out from it at the top and then runs around into the throttle body at the front of the engine.

This may help figure out the intercooler:

http://www.swedishautoparts.com/V70/Vol ... rgers.html

The TCV is usually mounted on the air box casing. It should have 3 small diameter hoses running out from it.

There are 2 types of TCV but yours should look like this (look at the last photo)

https://www.matthewsvolvosite.com/forums/vie ... 4&start=28

TCV looks like this:

https://www.google.ca/search?q=1998+Vol ... j1ue4zM%3A

Hope this helps.

On the transmission fluid. There are guys here that suggest the easiest and probably the least stressful on the old transmissions is to drain the transmission, measure what has been removed (around 3.5 litres if I recall), and refill using the transmission dip-stick hole the same amount you drained out. Then do it again after each oil change or the next 3-4 changes. This way you will change the fluid over time. If it is showing read and doesn't smell burnt then this is probably the way to go.

Neil.