2001 v70T5 210K little to no boost and maybe a miss...

carboncow · Post by **carboncow** » 02 Jul 2015, 18:09

Daily driver on freeway and cruises fine but little to no boost and it seems to miss above 3K RPM.

TCV has been tested with a good known one
compression test has 165lbs on all 5 cyl

What else?

Plugs are due to be replaced so going todo that tonight but suspect that would throw a code, no? Same with coil packs?

Nothing is showing on my Vida Dice other then a known 02 sensor issue that's been there for years.

Mentioned this issue a while back here: https://www.matthewsvolvosite.com/forums ... =9&t=69739

Post by **abscate** » 03 Jul 2015, 04:30

Coils and plugs don't reliably throw misfire codes, based on Board history I've read.

Check your coil pack resistances and make /break all the connectors.

Let's see a picture of those plugs, too.

carboncow · Post by **carboncow** » 03 Jul 2015, 07:35

ahhahaha!! But not really...

I had no idea coils could be bad w/o throwing a code. I did in fact find two coils not firing and another that was weak. I swapped them with good known ones out of donor car...but no improvement.

I reset all codes, scanned with Vida Dice and drove around to allow for adaptive. The car has light boost at lower rpm but will not go over 4K in while in N and I suspect in D. While reving in the driveway I get some studders intermittently at approx. 2.5K or 3K rpm.

EDIT: OK I read a post that said P2 cars will not go over 4K in N but I still have some misfires in N while revving...not constant. Going to order a new set of coils on ebay for $50.00...cannot beat that!

Worth noting the plugs didn't look bad to me but I have to run cooper in this T5 (2.3L) and thus they need changed more often. I got Autolite copper and the the car didn't like those...so back to NKG copper and it's a bit better.

As far as those coils I obviously was running better then when I started pulling coils and plugs and putting it back together to find it running worse...so I think I made the coils mad because there is no way this car would have run on the freeway to work every day w/o 2 coils working. Maybe one...but now that I got new plugs and good known coils it's driving the same as before.

Post by **precopster** » 03 Jul 2015, 16:21

What scanner are you reading the car with ??

carboncow · Post by **carboncow** » 03 Jul 2015, 17:35

Vids dice. No codes for non working coils. Starting to think MAF is to blame runs a bit better disconnected and boost is returning.

Post by **abscate** » 04 Jul 2015, 02:57

Take a good look at your induction hoses for loose clamps, splits, holes, etc. it's amazing how bad a turbo will run with a small leak

carboncow · Post by **carboncow** » 04 Jul 2015, 06:22

We have been all over the hoses visually. Any good trick of something to spray that might help?

Drove car two hours to the lake today. Boost is back with MAF disconnected for sure. Odd no CEL yet! Boost is still a bit erratic at higher rpm and load, with swap out TCV yet again when I get home.

TCV buzzes for a minute after I shut off car, but only sometimes. Is that expected?

Post by **abscate** » 18 Jul 2015, 13:35

You really have to undo the clamps and remove the 3 pieces of hose that connect the hard hoses to rule them out. It is too easy to miss a split with parts in car

carboncow · Post by **carboncow** » 19 Jul 2015, 21:07

It was clearly a case of coils not throwing codes...and appeared to be working at lower RPM but cutting out over 2.5K. I put in my coils from my other volvo and it ran well for a day until I lost yet another coil when hitting it hard above 4K.

Since I have to use the copper plugs they were replaced to with about 25K miles on them...they didn't look to bad but the new plugs made a huge different.

First time ever that I had a coil issue and no coil code.

PS. I bought $50 coils on ebay (for 5) to put back in the XC70 donor and although they seem to work well all 5 of them throw codes...damn. Now it's crying wolf 24/7.