- I was driving up to NH from Boston and the car said "Slow down or shift up". I figured I had a mis-fire as the engine idled poorly and felt down on power when accelerating on the highway.
- I limped the vehicle home. When restarting the car, there was a fuel smell, I interpreted this as the injectors firing for a few cycles on startup and not burning in the cylinder.
- Autozone read a Cylinder 3 and 5 misfire. I got a set of Denso iridium plugs, and Duralast coils (5) and replaced them this evening.
- When pulling the old plugs, the 3rd cylinder plug was dark, as if fouled by fuel. There did not appear to be excessive oil on the value cover.
- I think I've dealt with the "common issues" now, and basically now I can only think of harness issue, fuel issue, compression issue. Of those three, which are more common?


107K
2013 s60 T5 awd

 

I realized that I didn't say that I still have the problem - still feels like a misfire on idle and bogs on acceleration.

 

Have you checked the compression? My '03 V70 T expired when I lost compression on #3 and the estimated cost of diagnosis/repair far exceeded the then current value.

 

Thanks, I will do so tonight, fingers crossed...

 

issues with the fuel pressure sensor can lead to misfires. Did you scan for any stored check engine codes? Compression issues on a 100K engine are pretty rare but possible (any head gasket symptoms - loss of coolant/oil mixing etc). Fuel pressure issues would be more common. Harness issues usually are found in older cars not 5 year old models (just did the coil pack harness on my son's 2000 S40 for example)

 

Hi MT,

- I ran compression across the cylinders and cylinder 3 had a 0 pressure condition dry, and wet (w/ ~1/2 pint oil). Every other cylinder was ~150-160

- The scantool said fuel was around 49PSI at 2500rpm on the highway when it registered the misfire so fuel pressure seemed within range.

- I also don't think it is a fuel system issue because the plugs I installed last night all smelled a bit like fuel, including spark plug 3.

- Since the wet compression showed no change in pressure, I think rings are ok.

- I cranked the motor with plugs in, fuel pump relay out, and ignition out, and looked to see if any bubbles in the coolant overflow tank and there were none. No fuel air mixture. I didn't suffer from any overheating issues.

- I pulled the hose from the top of the crankcase (looks like it goes down into the PCV/oil separation system) and it was not visibly clogged. i looked down into the crankcase and it did not look like there was lots of oil sediment.

Suspicions:
Intake or exhaust value - will run a leak-down test.
- could be caked with carbon deposit and stuck open, perhaps caused by an abundance of buildup within the PCV system?
- maybe stuck somehow or not enough oil pressure to drive the valves, I've read about valve oil seal issues.

Oil jacket / Head gasket - I have been losing a lot of oil. Like 5quarts per ~3-4K miles. Could there be a leak to one of the oil jackets from cyl 3?
- I was monitoring the burn rate and thought it was the breather /pcv system. I should check the state of the EGR valve and see if that is clogged.
- Important to note however that I don't have any noticeable smoke out the tail pipe. I had a blown turbo seal on a previous car and that was smoky.

Worst, and possible case - may need to get a new head. How much does that run and where is a good place to get one?​​​​​​ The car is otherwise in great shape.

 

"cylinder 3 had a 0 pressure condition dry, and wet (w/ ~1/2 pint oil). Every other cylinder was ~150-160"

Don't understand - if this is indeed the case, #3 has a major problem

 

Yes, and continuing on with the diagnosis, trying to figure out next steps to identify where the air is going. The car has obviously been sitting and is not being driven. It's clear now that it's not ignition or fuel causing the misfire.

Based on wet test, I don't believe it's at the rings.
Based on coolant bubble test, and lack of oil/coolant mixture, lack of overheating issues, I don't believe it is the bottom end, or a crack leading to the water jacket in the block.

Intake valve / exhaust valve?
- valve oil seals?
- don't believe it is a bent valve but will endoscope, timing belt in good shape.
- suspect carbon buildup

gasket?
- Where are the oil jackets within the head-gasket - I can't find a diagram anywhere
- PCV looks clear, but didn't check EGR blockage, will check

 

+1 with Pretorien - If you have zero compression on #3, you will need to pull the head off to inspect. Could be a bent or burnt exhaust valve or a blown head gasket (usually head gaskets hold some compression or have low pressure in adjacent cylinders) - you can do a leak down test or push compressed air into the spark plug hole to see if it comes out the exhaust or do an inspection cam to view the valves. Don't see how carbon build up would cause zero compression - and stuck valves usually burn as a result.

 

Thanks, with regard to head gasket, the other cylinders are holding 150+/-psi, and I'm not seeing any air bubbles in the expansion tank. Could there be a leak to a oil supply/return within the head gasket? I can't seem to find a diagram.

I'll run a leak-down tomorrow. What is a good place to source a new or re-man head? Clearwater does not appear to have any for this model currently.

I'm imagining the possibility of an intake valve or exhaust valve possibly held open due to carbon deposits, is this a possibility? Image of cylinder 3's original spark plug on the right, all others look like left:

Lastly, I didn't have any overheating issues, or any coolant loss, and don't have oil in the coolant.

 

you can shop for a used head on car-part.com to price out the market. I'd also call around local machine shops for the cost to rebuild if it is a burnt or bent valve. Doesn't sound like the head is cracked or warped so the rebuild may be the way to go.

 

Thanks MT, Do you think this has anything to do with oil burn, or do you think that's a completely separate issue? I've been drinking up about 5Q every 5K miles. I was monitoring the consumption since my last refill when this happened. I will need to look at the EGR valve and the breather system.

 

Perhaps a holed piston? This would possibly pressurize the crankcase enough to blow some oil out -alternatively broken rings + badly scored cylinder wall?

 

Thanks Pretorien, I feel like the piston and rings might be fine because I poured about ~1 cup of oil into the third piston when I did the wet test. After cranking it, the the oil remained in the piston and maybe took an hour to leak out. I will check it out with the camera tonight. I will check for scoring. I think I'm able to source a "complete new head" for ~500 if the bottom end is ok.

 

Bad situation but closing the loop on this. I did some more diagnosis, but my Boroscope was too wide to 180-it and I lost the mirror attachment. At this point I've kind of thrown my hands up as it's my wife's commuter and she's been patient enough with this shade-tree monkey. Also, we don't have a garage and it is super cold in Boston.

I sent it to my local Indy. They leak-tested, boroscoped and removed the cam cover to check the valves and offered me three solutions. Their leak test was inconclusive, they were also not able to boroscope upside down (180 up at the valves).

I'll take back the old motor and take it apart on my free time for a post-mortem with some pics.

1 $2500 for a head replacement all in (clearwater quoted ~500 for a complete head as a part)
2. $4500 for an 80K motor (30k less than current) with a new timing belt, and replace any hoses behind the motor and a 6M warranty.
3. $500 to remove the head and inspect the underside of the valves, then decide on 1 or 2.

I went with option 2 due to a couple of rationalizations:
- I'll get to skip the 100k service interval and the next TB change will be 180K
- I get rid of all my cars around 180K and the amortization of the 4500 from 80K to 180k miles is around 4.5c per mile.
- The head option comes out to about 3.5c per mile from 110k to 180k
- I don't think option 1 would have resolved whatever caused the issue (which i believe is connected to an oil burn situation, and the PCV system.) The motor will come with a new PCV system.

 

Closing out the loop here, I got the head off and both exhaust valves were chipped to the effect of about 1 cm^2. Everything else looked fine. What is valve chipping a symptom of? Pics to follow.

Looks like the motor is fine, save two valve replacements in the head. How would you guys get rid of the motor (or recover some cash?). Would motor re-builders take the whole long-block to rebuild for some core charge? If so, who?