I'm new to these forums, and a new Volvo owner as well.

Last month when I saw a 2001 V70 XC AWD(191K) on a local online auction I decided to bid on it... Couldn't believe when I won the auction for $825.00.

I've always loved these machines, but as life goes for me, buying one has never been what I could justify as a priority, more of a want. My justification on this older one was that it would make a great Winter work car here in NE Minnesota.

There are/were a few issues with this older car... I had to replace one wheel hub assembly(Which was easy enough). There are a few other issues that I will eventually address, but for now my most pressing issue is what "I'm perceiving" as an "intermittent misfire".

Before I go further, I should add that I've gotten a diagnostic from a local auto parts store indicating that solenoid A(Gears2/3) in the tranny has issues. I've noticed different symptoms from that issue, but don't believe that it's relative to what I'm about too describe.

Lets start with my ride to work... I drive 6 miles on a 4-lane HWY(65MPH)... Followed by 9 miles on two rural 2- lane roads(55MPH)... Then I finish on 8 miles of gravel road.

First I'll try too explain when the symptoms occur... When I leave home, and hit the HWY, the car usually runs great. It set the cruise and go... When I turn off of the 4-lane the issues often , but not always begin... At this point I should say that I'll have to slow down, and make two more turns before I'm on the gravel... Sometimes the issue will begin after I've made one of those turns...

Now I'll try too explain the symptoms... After I slow down, then begin to accelerate, when I'm having issues, I can hear an audible difference in the cadence of the engine, as well as feel the difference in the sense of a vibration... Also, when the issues begin, the Check Engine light begins to flash(I know... Bad JuJu!) As I get up to speed, and reset the cruise, from day to day, different things happen... Some days the car will settle out, it will give me issues when accelerating from a slowdown then run great when it's up to speed.

On other days I can set the cruise on the rural roads then hear/feel and see(The check engine light) the car intermittently "misfiring(?)". It will run great, then have issues, then run great again.

One last thing I've noticed is on my trip back home... When I'm having issues as I hit the 4-lane, when I lay into the throttle to bring the car up to speed(65MPH), the misfire occurs on the low end of the RPM's. When I let the engine rev before easing too shift, the misfire clears up in the high revs...

Sorry about the long wind, and hope I've described my troubles well... Also hope too get some good replies...

 

First thing I would do is catch up on the scheduled maintenance. I think you have already. I would pull plugs and look, and check the coil primaries and secondaries. I am just guessing here but I think you may have 1 or more coils gone bad warm. As for the transmission you might try fluid&filter change if not previously done but often by the time it throws a code you're too late.

 

As far as the tranny goes, I believe that you are correct. When I initially checked the fluid my thought was that it was "too" clean... Meaning that it was obviously recently flushed... My thoughts were that either, the previous owner was on top of their maintenance, or there was an issue being addressed... The latter seems to be the truth.

Now for the coils... This is a new machine for me... Tho I have a bit of mechanical aptitude, I'm certainly not a mechanic... I'm an equipment operator at a Peat bog, and maintain mostly diesel equipment... So my question would be, how do I go about "checking" the coils? I believe that I have them located, but don't know how to troubleshoot them.

One more thing I should add is that it would seem as though one, or four of the injectors have been replaced... Four of them are orange, one is white... Not sure what color they are out of the factory, and got nothing about injector replacement in the Carfax.

 

I don't think there is much of a way to do practical coil diagnosis. I agree that is likely to be the issue and you ought to replace them.

With a scan tool you could at least see if the misfires are on certain cylinders. You would expect that. that would at least reduce the expense of it.

 

Coil diagnosis - you get a known good coil and measure the resistance across the primary and secondary windings. then you pull and check each installed coil - primary resistance, secondary resistance, and then see if there is any continuity at all between the primary and secondary, which would indicate a breakdown of the dielectric. Any decent, sensitive digital multimeter is adequate for this. If you do find a bad coil do not be surprised to find associated wiring or controls have also failed, the coils are a high energy component. As for finding one "bad warm" what you'd likely find is what looks like minor or intermittent leakage between primary and secondary when you are checking the coils or a coil whose resistance at primary or secondary is an outlier. Replace those leaking and off-spec coils.


As for the injectors there may not be a problem. You could look for identifying marks on the injectors then look them up to find the spec. You could get a couple used ones matching the four then send them all out to be cleaned and flow matched.

 

Okay, so I cheated, and took a little shortcut... I drove the car to town and back, about a 50 mile round trip... When I got home I immediately checked the coils by physically touching them, and found one that was noticeably hotter than the rest... Replacing the hot coil has fixed about 99% of my issues.

It seems as though I've got another coil that's still giving a little bit of an issue... I'm thinking that I'll probably have to go threw the troubleshooting process to find that one, because I don't believe that it is bad enough yet to get hot.