2004 s40 1.9 hard start/wont start

[HeavyFuel]

Just now checked compression.
1. 180
2. 178
3. 183
4. 179

Put new spark plugs in, and it started very hard, ran rough and "weak" (for lack of a better word) for 15 seconds or so, then smoothed out and ran great. No smoke. Drove it for 15 miles at highway speeds. Shut it off, and started it warm, fired right up.

I have attached a photo of the plugs i replaced.

I will try it cold again in the morning.

20180905_200934.jpg

[HeavyFuel]

Started it this morning and drove it to work. It started easily, ran a little rough for 5-10 seconds, and cleared up after that. I drove it 30 miles into work, shut it off. No issues, no smoke. Smoke in earlier post must have been cleaner i used for IACV & throttle body. After about 1.5 hrs of car sitting at work, i had to drive to a nearby plant, and it started a little rough again, but cleared right up, same as drive into work. If it sits after driving any time over an hour, it starts a little rough. If i start it right after shutting it down, and stiil hot, it starts with no hesitation or roughness. Looks like possibly it is fouling the plugs (contamination from either small leak in head gasket, or oil from turbo intercooler hose into throttle body?) When i cleaned throttle body, it was a little oily inside the hose and throttle body. I fear it will escalate over time to a no start condition again.

[alschnertz]

Sounds like things are improving.
I wonder if you had a bad tank of gas.
Running a few cans of fuel system cleaner (that also treat water in the fuel) probably wouldn't hurt.

[HeavyFuel]

I hope it clears up. The PO said he owned the car for about 1.5 years, and had this hard start/no start issue for a year before he decided to sell. He claimed he changed the timing belt, and coil packs in attempt to fix it, and only put 2000 or so miles on because of its issues. He said the turbo was changed by the owner before him. I dont know why that was done. It appears this car has a history that is partially unknown, at least by me.

[HeavyFuel]

I have been driving it since last post, and it has started fine so far. I think (hope) what was going on was due to the failed turbo two owners ago. Heres my hypothesis. Owner #1 had turbo failure, and had turbo replaced. Owner #1 sells car shortly after this to owner #2. Owner #2 drives car for 6 months, and begins having trouble with hard starting (as he stated). He has many parts replaced trying to fix problem, but no one thinks to clean all the oil out of the turbo hose going from turbo to radiator to throttle body (caused by failed turbo). Residual oil from prevoiusly failed turbo keeps getting pushed up.into throttle body, fouling plugs. Owner #3 (me) buys car, scratches head, reads related threads and asks questions on Matthews Volvo Site, and decides to replace plugs and clean oil out of throttle body and post-turbo hoses. I did get quite a lot of oil out of there. So far, seems like the answer.

[alschnertz]

I like your hypothesis. It could be wrong, but your approach makes sense to me instead of just changing parts.

KISS (Keep It Simple Stupid)!
This is not an insult to you, it's something my dad always said to me.
Always look at the basics. Can't believe how many times I've just taken something apart, cleaned it, reassembled and found it working as designed.

[HeavyFuel]

It started good for a few days, then slowly became more difficult. Now today it started a bit rough, and i drove it a few miles. I then parked it at home for a couple hours, went out to use it again, and it wouldnt start. I pulled two of the plugs, and they look wet from coolant. Not a good sign. Seems to me that would indicate head gasket. Only thing is, compression is plenty high, all cyllinders around 180 psi. Never overheats, and no milky looking oil in dipstick or under oil cap. I do hear coolant flow through the heater core area while driving though.

[HeavyFuel]

After thinking on the latest developments, i have a question. How does the intercooler on the s40 work in regard to interaction with the engine coolant. Is there any opportunity for a damaged intercooler to have coolant enter the turbo charged air, therby entering the combustuon chamber? Or, is the intercooler not in contact with coolant? I ask because i want isolate the origin of the apparent coolant on the spark plugs.

[alschnertz]

I don't see how the intercooler on my '01 (which I believe is the same as an '04) has any contact with engine coolant.
From what I see and understand, it is simply an air-to-air cooling device. Hot (turbocharged) air flows through it (like liquid coolant would) on its way to the throttle body and said hot air is cooled by the ambient air flowing through the fins of the intercooler.

It is also my understanding that the turbocharger itself is "water cooled." Meaning that the engine coolant circulates around the turbocharger in a similar fashion as it circulates around the engine.

[HeavyFuel]

The reason i ask, as you may have guessed, is so i can rule out sources of coolant in the combustion chamber. I still hope that the coolant is residual, from the previous turbo failure. If the turbo is, in fact, "coolant cooled", the there is the possibility that the new turbo was improperly installed, and there is coolant coming through the charge, into the intake. If it's not turbo related, then its head gasket.