'04 V70 NA What have I done, won't start

Faust · Post by **Faust** » 05 Aug 2017, 18:47

My '04 V70 non turbo was displaying all the signs of a blown head gasket. Overheating, hard starting and rough idle, water in oil. With 200K, I thought I would try a little blue devil. On their instruction, I pulled the plugs looking for "white" ones, which I was to leave out to improve chances of a seal. Well, I did that and poured the Blue Devil in thorough the radiator hose. Leaving one plug out, The car started, but ran very poorly, not able to exceed 500 rpm. I then noticed that the radiator hose had disconnected, but didn't seem to have lost much. I bought another can of BD poured it in and installed a new hose clamp. Now, it won't start at all (BD requires 50 minutes at idle to seal). Aside from pulling and reinstalling the plugs again, and checking for spark at the coils, I have done little. Not sure why it might be fuel, I tried a little ether. No help. I have checked the coil packs against a picture to make sure I had installed them in correct order. Any ideas where I could have gone wrong?

Georgeandkira · Post by **Georgeandkira** » 06 Aug 2017, 06:51

Maybe you have more than one problem.
I can't even guess as I have no track record with failed engines of our type.

I'd check fuel pressure at the rail with a gauge. Consider changing the gas filter 'cause it's so often overlooked.
I'd also do a basic compression check. You'll need a gauge with an extension.

Faust · Post by **Faust** » 06 Aug 2017, 07:31

I should mention that before beginning to pull plugs, etc. The car behaved normally, other than the usual hard start and "stumble until cleared" usual with a head gasket leak. It all seems to have begun with pulling and re-installing the plugs.

I did try a compression test with a "new" HF compression gauge. I think it gave a correct reading on the first cylinder, after that , it would not exceed 90 psi. Fortunately, HF has a"easy return" policy. Not sure why I thought there might be a fuel problem, but I tried a little ether to no avail. It seems to occasionally fire on only one cylinder.

Post by **mrbrian200** » 06 Aug 2017, 23:20

Just a theory. Idling with a plug removed - very unbalanced - the timing belt may have skipped a few teeth. I'm thinking how the tensioner might act under these conditions and whether it could induce just enough slack at times to skip, probably around the crank.
I would check it.

Faust · Post by **Faust** » 07 Aug 2017, 03:36

A good thought. I notice that when I crank there is an occasional firing of one cylinder. I have been trying to explain this to myself. Having "jumped timing" does offer an explanation. There must be alignment marks that I can see. This suggestion makes more sense than anything I have thought of (brought up with "timing chains"). Thanks.

Georgeandkira · Post by **Georgeandkira** » 07 Aug 2017, 05:13

You'll find timing marks on the face of each cam gear (faint scratch) and a "modified tooth" on the crank's sprocket.
The sprockets' marks align with corners of the cam gears' plastic shroud.
The crank sprocket's mark is at 12.
Removal of the cam belt cover is required.
I would've thought that a jumped tooth (or two) would cause a check engine light but I do not know.