need help debugging my 2007 XV70 turbo I5 AWD

drgian · Post by **drgian** » 26 Jan 2019, 21:32

2 years ago I bought a 2001 cross country with a clearly blown headgasket (pressure in the radiator bottle), anti-freeze shooting out the back. Thanks to help mostly from this forum and a few friends I tore her down and replaced the head gasket and she ran great for about a year.
I gave her to my 18 year old and they got along great. But you know the story, she was looking down at her phone and rear ended a stopped raised F350. The pickup had hardly a scratch but the Volvo was totaled out. I had full coverage so we got a 'new' one, a 2002 and this one has no issues and I still have the wreck.

Now it's my next kid's turn. For her, I found a 2007 who's owner was told by a mechanic that something serious like a head gasket is wrong so I got it cheap. It's a nice car, clean, all the features. I got to it last weekend and he's what I found.

The symptoms are these 1- idles rough, it seems clear one cylinder isn't doing anything. weak bumpy accelerator; 2- code reader says misfire cylinders 1 and 3.

otherwise I can find NOTHING ELSE WRONG*. There is no pressure building up in the collant reservoir, no hint of oil in there. No foam under the oil cap, the exhaust look and smells fine. However when she first starts a few drops of water drip out the exhaust and I an see small amounts of oil floating in the drop like a little eyeball retina.

*Update; one other clue, when I first looked her I could see someone had replaced the wiring to the fuel injector on 1 and 3. i think he actually replaced those 2 with used injectors. I pulled the coil packs and the injector in #3 was burned down a tiny nub. I'm thinking the local mechanic replaced all 5 plugs and this one burned up during the 3 hour drive home after I bough it. I replaced all 5; no change.

So the question is what causes

1) loss of power
2) spark plug way premature burnout
3) OBDII misfire codes and nothing else

I had replaced the coil packs on the 2001 before it was wrecked so I tried swapping those out for cylinder #3 and there was no change at all

Last, and I'm afraid most telling I added a quart of Lucas Oil and did seem to make a noticeable improvement. I don't' take this as a good sign.

Any help at all will be greatly appreciated!

drGian

Post by **chrism** » 26 Jan 2019, 21:55

How about doing a compression check on all five cylinders to see if you even have a healthy engine to begin with? Then, if compression is good, delve into the ignition and fuel systems.

Post by **RickHaleParker** » 27 Jan 2019, 06:59

"I pulled the coil packs and the injector in #3 was burned down a tiny nub."

Err ... rewriting that sentence would be a good thing.

drgian · Post by **drgian** » 27 Jan 2019, 10:20

'the spark plug in #3 was burned down to a tiny nub'

I will check the compression, I was just wondering if the burned plug meant something, I haven't ever seen a single burned up plug before.

EngineeringBloke · Post by **EngineeringBloke** » 27 Jan 2019, 10:47

1. Do you mean fuel injectors in the following or did you mean wiring to the coil packs?
2. Why do you think he replaced 2 used fuel injectors?
3. Did you replace the coils, fuel injectors or plugs?
4. Was the engine oil a quart low? What is the Lucas oil you added?

*Update; one other clue, when I first looked her I could see someone had replaced the wiring to the fuel injector on 1 and 3. i think he actually replaced those 2 with used injectors. I pulled the coil packs and the injector in #3 was burned down a tiny nub. I'm thinking the local mechanic replaced all 5 plugs and this one burned up during the 3 hour drive home after I bough it. I replaced all 5; no change.

Post by **RickHaleParker** » 27 Jan 2019, 10:55

drgian wrote: ↑27 Jan 2019, 10:20 'the spark plug in #3 was burned down to a tiny nub'

Think back to when you took it out. Was it loose?

Post by **abscate** » 28 Jan 2019, 05:12

Could be a spark plug defect.

Compression test is definitely next step in a suspect engine. It's very common for a worn out engine to not show any nasty symptoms. Even the exhaust gas in coolant test only gives definitive positive results, a negative test is only 75% reliable, by my estimate

Klausc · Post by **Klausc** » 28 Jan 2019, 12:18

Don't worry about the spitting tail pipe, that happens when the muffler doesn't get hot enough to evaporate the condensed water.

Pull the two injectors and test them in a cup to see if they spray correctly while the starter is spinning the engine. Sounds like #3 isn't working.

When doing a compression test on a cold engine, expect low but consistent values across all cylinders. If #3 is very low, add a table spoon of oil through the spark plug hole and wait 5 minutes before retesting. Checking rings.