2002 S40 150kmiles

My wife is complaining about her car overheating only when the ac is on, and it appears to be intermittent. I doubt that the extremely hot weather in Denver is the culprit. I did find that the antifreeze overflow container was a little low - I filled it about a week ago, and it's low again. My thought is probably the water pump, but I can't find it to see if it's leaking at all. But the overheating goes away as soon as she turns off the AC... which really seems weird to me. I've only seen the overheating for a brief time going up hill... as soon as I made a sharp right turn it went down significantly.

The CEL has been on so I went to autozone to get the codes pulled
P0301 - Cylinder 1 Misfire
P0304 - Cylinder 4 Misfire
P0420 - Cat Converter 1
P0299 - Turbo underboost

I did change out the cylinder 1/4 coil the other day and it's running much smoother, so maybe those codes just haven't cleared yet.

Other possible symptoms:
Hard time starting
Low pitch clicking until the engine warms.
Loosing oil - it's almost dry by the time it's time for an oil change - but the oil is not finding it's way to the ground... I have seen a little (not much and usually just after starting it at cold) blue smoke out the exhaust... so it's burning at least a little bit of oil.
Electric fan runs 5-10 minutes after turning off the car

I'm starting to think that I have a serious problem with this engine, but I'm not sure.

Anyway - any help would be appreciated.
Tindel

 

The water pump is driven by the timing belt and located on the pax side of the engine under the timing belt cover. It's very hard to see without taking off many things. If coolant is not making it onto your driveway then I'd look elsewhere.

There are several places coolant can leak including small coolant hoses to the turbo center section (has oil hoses too). Unfortunately there are many ways coolant can make it out of the system. Can you smell coolant with the hood open when the engine is running? An active leak will smell sickly sweet. Does the exhaust smell like coolant? A warped or cracked head from overheating can let coolant into the combustion chambers or into the oil.

With your low oil, low coolant, cat convertor 1, and low boost it could be the turbo center section is wore out letting oil and coolant into the turbo. Don't buy a new turbo on my guess though.

I'd keep the oil and coolant topped off everyday and watch it closely to see if it gives you more symptoms. Have you pulled the spark plugs to see if they all look the same?

EDIT: The low pitch clicking until the engine warms is a symptom of a leak in the exhaust manifold from a loose nut on the exhaust stud. On mine it was always right above turbo. You can feel it after removing the heat shield on a cold engine. I fixed it with a stop nut.

 

Thanks Hudini!

Sorry it's been so long, I've been VERY busy at work, and the car doesn't overheat when I just go back and fourth to work (7 miles each way), so my wife and I have traded cars for the last month. So I'm just now getting to troubleshooting this issue.

I did change out the t-stat yesterday. Then I went to get some new spark plugs at the stealership ($42! Yikes!) and I started coming home the car started to get hotter than normal. It never did overheat. When I turned off the AC it cooled down. Then I'd turn the AC back on and after a while (not right away) the car would start warming up. So I did some checking once I got home. I couldn't get the car to overheat while idling in the driveway. I then rev'd the engine to 2500 rpm and held it there and the temperature started going up again.

Before I left this morning I did note that the radiator fluid level was good, but may have been a bit low because I changed out the t-stat last night. I forgot to check the oil level. When I got home the coolant tank was empty.

The trip to town was on the order of 30-40 miles round trip.

I did note that the ac only really blew cold just before the temperature started rising.

I don't know of anything else in the coolant system that would cause this to happen other than a stuck t-stat.

Any ideas?

 

I believe you have a coolant leak if the tank was empty after returning home.

First check the oil level. Is it full to low or above full? Higher than full indicates coolant leaking into the oil. The oil will also appear like chocolate milk. Here is a pic of one of my engines after a coolant leak.


If you cannot see any obvious leaks between the engine and radiator and heater core then remove the heat shield above the turbo and look at the small hoses on the back of the engine that cool the turbo center section and heater core. On my 2001 I had a small hose cooked by the turbo to start leaking down onto the cat convertor.

Bottom line, the coolant reservoir tank should not be empty after a 30 mile drive.

 

I agree completely, however, I had lost some coolant from changing the thermostat yesterday evening, so I figured the coolant tank being empty was just due to filling the radiator again.

I will probably take the heat shield off tomorrow and see if I see anything obvious, but I'm not sure I will... I haven't seen any

I did change the plugs tonight. All looked somewhat normal... not sure of the last time they were changed. The tips were a bit white and the surrounding threads were a bit charred. Plug two was covered in oil from the time I didn't quite get the oil into the engine and it poured onto the head.

 

I agree with Hudini. It sounds like a blown head gasket. Check to see if there are traces like milkshake-colored oil under the oil refilling cap.
Also check if there are bubbles of air coming up into your radiator.
Be sure the engine is cold as you need to remove radiator tank cap before starting.

 

I looked for chocolate milk and didn't see any...

So, I did some more digging... and found that the radiator had a bunch of cotton from the cotton wood trees in it! Blew it out with the air compressor the best I could, and it's not overheating anymore. Any idea why the air condenser, and tranny oil cooler fins are more open than the radiator? Seems backwards to me... but I digress. Would there be any harm to just spraying some water in there to try to get more of the cotton out? Also - If I have to take the radiator out at some point - how would I get it out of there? There's a big air intake going to the throttle body that was in the way... It doesn't seem to be filtered either, which is strange to me, but this is my first turbo vehicle, so maybe they're different.

Now, I get to think about some of my other problems on this car. While I was working on the car I noticed a few things.
1. It looks like there is some burnt oil on the flap in the throttle body. How could it get there? It wasn't like normal carbon that you could blow out, or take out with a rag... it was more of a golden sheen over the top of everything... it was darker in some places... I wish I had taken a picture.
2. There was a strong gas odor near the throttle body. That seemed strange. I've been having problems with things feeling sluggish and the engine slowing while idling down to 500rpm or so... maybe this has something to do with it.
3. Still losing quite a bit of oil. I tried adding some STP to see if that would help.

 

High mileage cars demand TLC, don't they? The big air intake is connected to the air to air heat exchanger. This is a radiator for hot hair from the turbocharger. The air flow starts just below the drivers side headlight via tube to the air box with the air filter. Then through the Mass Air Flow sensor to the turbo compressor. It comes out the compressor, over the engine and down to the air/air heat exchanger then out the top of that to the throttle body. Compressing air makes it hot which is bad for power so the air/air heat exchanger cools it back down.

You can backwash the radiator anytime. If you have allot of damaged fins you can buy a "fin comb" like the a/c guys have who work on your home compressor. Removal is just taking things apart until you have enough room to lift it out.

The dirty oil film on the throttle body butterfly is from the PCV system. Throttle body cleaner sprayed generously as you hold it open helps clean the small passages. Realize your whole intake tract is covered with that mess too. I soaked mine in mineral spirits when I had it off for engine work 2 years ago. I washed lots of gunk out.

The strong gas odor near the throttle body is not good. In that area you have the fuel feed line into the fuel pressure regulator attached to the fuel rail with fuel injectors. Can you see any yellow discolored areas where fuel has been wet then dried numerous times? My old '86 240 had a leak in the feed line behind the head. It sprayed right on the fiberglass insulation. It would evaporate before running to the ground but you sure could smell it. Took me forever to find that leak.

losing oil and a really gunked up intake could be related to a clogged PCV system.

 

Well - I think I found the fuel leak.

1 - shows some of the dried fuel
2 - This vacuum hose (?) going to the intake manifold from the fuel pressure regulator (#3?) is cracked badly and needs replaced. It is also leaking fuel out of the cracked hose, I think. I'm guessing that fuel coming out of this hose is a sign that the FPR is broken / bad. This would also explain why the throttle body is so gunked up.
3 - Fuel Pressure Regulator?

Concur?

Do I have to get these parts from the dealer?

 

Looks like you have found your fuel issue. You can find the FPR at more than the dealer these days.

IPD : Fuel Pressure Regulator - S40 V40
Advance: Buy BWD/Intermotor Fuel Pressure Regulator 24114 at Advance Auto Parts