2002 V70 rough idle ( slipped timing belt)

Canadian Moose · Post by **Canadian Moose** » 22 Sep 2016, 18:33

A small back story before I get to the actual problem. I bought a 2002 V70 2.4T with a blown engine so I don't have much history on the car or how it ran prior.

I swapped the engine with a 2.5T using all the accessories from the 2.4.

The car runs and drives decent but I am seeing an issue with rough idle. It seems to occur once the engine is warmed up. It runs better when cold. Almost feels like a slight misfire. When the car idles rough I can see all the lights dim ever so slightly. If I put my foot on the gas even a little bit the car will idle fine. The check engine light is not illuminated.

So far I replaced the plugs gapped to 0.030. Next I was planning on doing the fuel filter. I read about cleaning the throttle body which I did before reinstalling it back on the engine. All the vacuum hoses were replaced with new ones. One thing that it needs is the upper engine mount as the rubber inside separated. I don't think that would cause the idle issue that I am experiencing though.

All the intercooler pipes were soaked with oil due to worn out turbo so I suspect the MAF to be soaked as well. Where abouts is it located if I were to clean it?

Anything else I should check?

Another question that I have is with regards to the headlights. My headlights automatically turn on when the car is running even though the switch is set to off. I am assuming this is a daytime running lights function. The tail lights also come on at the same time. Basically keeping the headlights on all the time? I know on other cars DRLs only activate the headlights or parking lights in the front but not the rear. Are mine messed up or is that how DRLs work on Volvos?

1991 gmc jimmy · Post by **1991 gmc jimmy** » 23 Sep 2016, 04:47

I would like to know also about the headlights staying on also.

Post by **abscate** » 23 Sep 2016, 05:38

In Canada I think you have a different DRL spec than US. I believe full lights on is correct for you

Post by **jonesg** » 23 Sep 2016, 06:38

I would suspect O2 sensor and cat converter if the turbo is blowing oil.
Did you read any codes?

I just replaced my turbo, its doing the exact same thing, poor idle and slightly dimming headlights when idle stumbles.
I know I can clear the codes and it will clear up but it will come back again in 3 weeks until I fix it.
I believe I can hear an exh leak , will be checking it at the flew pipe for leaks.

Canadian Moose · Post by **Canadian Moose** » 23 Sep 2016, 06:44

abscate wrote:In Canada I think you have a different DRL spec than US. I believe full lights on is correct for you

No other cars around here have tail lights that are on with DRLs. Is it possible to disable the taillights with DRLs?

jonesg wrote:I would suspect O2 sensor and cat converter if the turbo is blowing oil.
Did you read any codes?

I just replaced my turbo, its doing the exact same thing, poor idle and slightly dimming headlights when idle stumbles.
I know I can clear the codes and it will clear up but it will come back again in 3 weeks until I fix it.
I believe I can hear an exh leak , will be checking it at the flew pipe for leaks.

Aren't the codes only present when the Check Engine light is on? Mine is off.

The turbo was just rebuilt.

Post by **abscate** » 23 Sep 2016, 09:01

You should try reading pending codes even if the light is off. the light sometimes only comes on after several reads of codes generated by the failures.

In the States, DRLs have no taillights - one of these reasons I don't like them, as we get people driving at night without taillights.Pet Peeve.

Canadian Moose · Post by **Canadian Moose** » 23 Sep 2016, 09:42

Ok I'll try reading the codes. Do I need a special code reader for a Volvo or can I just use a universal OBD2 reader?

Also, this car came from the US so I am surprised it has both head and tail lights illuminated.

Canadian Moose · Post by **Canadian Moose** » 23 Sep 2016, 19:33

Checked the codes tonight - there are none.

Fuel filter replacement made no difference. One thing I noticed the problem doesn't start immediately when the car is started. You gotta let it sit for a couple of minutes and let it warm up before it starts acting up. It really feels like a bad coil. I tried unplugging one coil at a time which actually made the idle stabilize. It ran a bit rougher but the idle was smoother.

Post by **abscate** » 24 Sep 2016, 01:16

If your car was legally imported they make you change the lights to Canadian spec st the border before it comes in.

Pull the plugs and let's see them in pics. Buy one coil and replace one at a time until your idle smooths

Canadian Moose · Post by **Canadian Moose** » 25 Sep 2016, 12:23

Got another coil and tried swapping it around this morning, made no difference. I did notice that other coils have small cracks on them. What are the chances that multiple coils are shot?

I pulled the plugs and they all appear to look fine. Also did a compression test and all cylinders are reading good - about 135 psi. Also swapped over another throttle body which was nice and clean. Lastly I swapped a few sensors and a couple of vacuum solenoids over which made no difference. I am at a loss now.

It definitely runs fine when it's cold for the first few minutes. Then when it warms up a little it starts to act up. Still no codes.

One thing I noticed is that the rad fan never comes on but the temp gauge always sits in the middle of the gauge or 1 peg towards hot.

Does Volvo have fail safe cooling on their engines where the computer shuts off one cylinder at a time to prevent overheating so you can limp the car home?