2004 V70 NA poor running, starting, head gasket? Topic is solved

[abscate]

There are three grounds on the coil

The M6 bolts we tightened on each coil grounds by touching the head. As long as the bolts are form, they are good.

The coils are fired by ground8ng through the ECU, not much to test there

There are two more harness grounds on top of the cover, look for a bunch of 2 or 3 wires held to the cover by a M6 bolt, 10 mm head. Those two grounds ground the number 3 terminal to the cam cover.

I’m guessing the indie has a good Snap on tool diagnostic but no VIDA. I think you need VIDA to scan the throttle body, not VISA. ( ooh, that’s a good one)

[precopster]

I'm concerned that the whining is the transmission due to coolant loss through the transmission cooler built into the radiator. What brand of radiator is fitted? Some brands don't cope well with overheating/lack of coolant a number of times.

Please be sure to check the quality/color of your transmission fluid.

The ETB is made by Hitachi for 2003/04 non turbo P2 5 cylinder cars. These were replaced by the Bosch units in 2005 and upwards. I have no information on how to test them and haven't had one through my workshop.

[oragex]

The throttle body (is that what TB refers to?) cleaning sounds a bit out of my realm. Maybe not, but have never done this. Unless you mean just squirting in that cleaner and revving. That I can do...

It's easier than replacing the air filter. Just undo the screw clamp at the large hose on the throttle body, toss the hose, then keep the valve horizontal with one hand and wipe everything around with a wet cloth insisting near the hinges. Saying this because on mine I have to do it regularly, it gets dirty and drops the idle when I come to a stop.

[precopster]

A "good" non turbo will have around 200 psi on the cylinders. Your car is approaching a no-start threshold with those low numbers. Some Seafoam soaking in the cylinders may bring them up, especially if you rotate the engine by hand to help get the product into the piston rings.

[oragex]

Just a side note, my experience with sea foam on these Volvo engines wasn't that good at breaking free the rings for one small reason: these engines sit tilted back by some 5-10 degrees. If the rings are stuck, the fluid will escape quickly at the rear of the piston and will less likely penetrate all around the ring (even less so in the second compression ring). The only work around would be to park the car nose dowwn on a very steep incline.

Just for the sake of the subject, I have the feeling that the compression rings get stuck when the PCV is neglected for a while. The positive pressure then blows too much oil into the ring groove which gets gummed after a while. Reason why I recommend replacing the PCV timely before it starts failing. But this is already off topic.

[precopster]

Ramps will fix that or just jack it up at the rear.
Of course cutting the front springs for that low mean look will also aid that process

[abscate]

The compression gauge used read low on my T5, so I’m not sure that’s the problem to focus on here. Remember the car started and idled easily in first rework. Something in engine management is not right and is rearing it’s head on occasion.

[precopster]

A network image in Vida of all the modules would be the place to begin check if any are red or have communication issues.

Sometimes a bad earth to a module can cause all sorts of havoc.

[E Showell]

Anybody check the ECT? Hard start symptoms sound suspiciously like a bad ECT, especially after a possible overheat. Occam's razor at work here ( man, that Occam could really use a shave, eh?) the coolant loss could be as simple as a bad expansion tank cap. Lack of a closed system can boil away coolant pretty quickly and can be a little hard to detect. Any whiteish residue around the expansion tank cap. Also, if the inclination is to keep the car, I'd replace ECT and thermostat anyway, so you wouldn't really be throwing parts at the problem if you chose to replace them as a matter of course. Coil packs well past their sell by date at 177k.

[Roger_850T]

To me, those compressions sound low. Although I think I also read that the gauge used is known to read low, so maybe not so much. Still, I've seen a timing belt slip a tooth or two before, especially when being inundated with snow, which I think was the original incident. So, it might be worthwhile to meticulously verify the camshaft timing, just to be sure. (Mine was off for other reasons, but had ~105psi compression across the board, like this one, so it makes me wonder.)

I agree the coil packs are old, and probably should be refreshed with whatever engine you end up with in the car. If the misfires move with the coil packs, then that's a pretty good indication. When mine started throwing random misfires at 156k miles, I replaced them all (because I wanted it to be reliable,) and the misfires have not reoccurred. But coil packs would have nothing to do with loss of coolant.

If this was mine, I would:
1. Pressurize the cooling system cold. (When hot, leaks can go unnoticed if the coolant vaporizes.) If nothing obvious, leave it at 10-15 psi overnight. Look for leaks the next day. Also significant - whether it does or does not hold pressure. Ideally you can park it in a garage when you do this, so that any coolant drips will end up on the floor, and you can trace it back to the source.
2. Inspect inside of each cylinder. Looking for coolant (from the overnight pressurization), and/or one being nice and shiny, indicating coolant ingestion over time. I have an inexpensive USB borescope that's ideal for this, but for just looking for coolant, a flashlight and eyeball may be sufficient. Look for coolant pooling on the back side (lowest side) of the piston.
3. Meticulously inspect all of the intake hoses. A pretty minor hole in an air hose can cause many of the drivability issues you describe.
4. Carefully check the camshaft timing. I expect to see 170-180psi on a turbo T5 engine. When my cam timing was off, I saw ~105 on all 5. The fact that yours are all low indicates a bad gauge (as suggested), or incorrect valve timing. By carefully I mean pop the cap off the back of the camshaft and use the tool that locks it in place, or at least visually double check it. Don't rely on any past paint marks on the cam gears.

I hope this helps - good luck!

Roger