(2002 S40)

I was driving into work the other morning and once I hit a traffic light I noticed my car had smoke coming from under the hood. Luckily the light turned green as I saw this so I drove the 50 yards into the nearest parking lot and turned my car off. The thermostat did go up to 2 or 3 notches short from red but DID NOT get into the red zone and my fans cooled it down fairly fast. The coolant exploded from my reservoir cap...

After work I got a friend to drive me up there so we could check out the damage. No hoses were popped in fact they felt just fine (sadly)... My friend said that there was A LOT of oil in my coolant and I agree, it was half way to full the other week and now its not even touching the dipstick (I didn't touch the car all last week either, yay holidays!). The car still cranks up just fine so I don't think its a warped head.

My friend and I have come across 3 things that could be wrong with it from doing the research we could...

1) *The most likely* A blown head gasket, mainly around the water jacket and oil port. That would explain the dramatic loss in oil suddenly and the pressure build up for it to explode out of the reservoir cap. My timing was off a little just a few weeks ago which I'm sure wouldn't help this if not cause this. I don't believe the seal around the cylinder has failed as the car runs fine still so I don't think a leak down test is necessary. I could be wrong though...

2) A bad radiator. To my understanding oil is flowing to the radiator and one of the walls may be cracked or something.

3) A bad Turbo. Which could explain the pressure but unlikely since I was driving for 20 minutes already around 55 mph and then a final 10 minutes on back roads doing 45 mph.

4) A previous problem that I'm not sure if it could have something to do with it or not. As I stated above my timing belt skipped a few teeth a couple weeks ago due to my CVVT gear's plunger leaking oil and the belt being old. Maybe the CVVT gear's leaking plunger has caused this oil/coolant mixture? Could that build up pressure to have it blow out of the reservoir cap? I haven't done research on this theory yet, it just crossed my mind as I was typing.


I am currently pricing parts as if the head gasket were blown. If anyone happens to have a break down on how to tear down the engine to replace that or any special tools that might be needed I would greatly appreciate it if you could give me a heads up on it.

Thank you everyone for any help you can provide!


(To anyone that thinks their hoses might be bad and you are looking at replacing it with a normal heater hose don't bother calling the dealership or any part stores they can not pull up any specs on the hoses... I haven't found the specs for the hoses online anywhere either... I think its best to just pull it off and take it into the store or take a small cutting if you can spare it...)

 

Oil in the coolant is definitely not a good sign...I think your guesses are good. What you really want to make sure you figure out though is what caused the headgasket to blow. I'm told they don't usually go without something having taken place first (i.e. a previous overheating resulting in a warped head for instance).

I came close to going into the red zone a couple of weeks back and it turned out that my rad fan's lower setting was not working so the fan would only turn on to high setting once the temp was already too high (turned out to be a blown fan resistor). This would be a good example of a possible underlying problem that could ultimately resut in a warped head. Either way, I guess that when you open it up, you'll be able to confirm whether or not the head was in fact warped which would help your trouble-shooting. Good luck!

Here's a guide for how to take a variation of your engine apart - you'll note though that this guy did it without the cam locking tool which I think was a bit nuts but ultimately he was successful...impressive.

Cylinder Head Transplant B4204S Engine - Volvo Owners Club Forum

Re #3 and #4 - not sure whether a bad rad could have caused this but definitely not a bad VVT.

 

Ok so I have taken the head off and the first thing that I noticed was that the ALL cylinders were FILLED with the mustard yellow goo formally known as coolant and oil. The gasket did have some small damage to it and it was pretty swollen. I also noticed that there was no coolant in the valve cover section so its not coolant mixing into the oil , but oil mixing into the coolant. There was some discoloration on the head where the gasket was most swollen which leaves me to believe that there was coolant/oil sitting there and getting absorbed into the gasket.

My biggest question is why were ALL of the cylinders filled? It wasn't running rough before I replaced the timing belt. The only thing I can think of is a COMPLETE failure of the gasket between each cylinder. However I only saw 1 spot on the gasket for 1 cylinder that was slightly looking damaged-ish...

I'd be more than happy to listen to any theories or ideas that could lead to the cause. All I've got is its old/bad gasket...

 

Brave guy - good on you for taking that job on. My guess would be that head was deformed enough that severe leaks had taken place. Be sure to inspect all valve covers (while the head is off) just to make sure they all look good and round, get a new gasket, get the head machined to ensure it is flat and throw it back together. You should be good. Good luck!

Let's see some pics!

When it's all back together just be sure that you very, very carefully monitor car performance because my understanding is that these cars don't often have HG failures without an underlying cause (i.e. fan wasn't running properly, cooling system breach leading to low coolant levels, etc...). If course, if you also had exhaust fumes coming into your cooling system as a result of the HG failure I suppose this could have prevented the coolant from maintaining the proper temp leading to an overheating condition...

 

I have a 2002 s40 also. Did you happen to take any pics of taking the head apart? I need a new head gasket as mine is leaking exhaust gases into the cooling system. Already removed the radiator as that had gotten a hole and pulled all the hoses and the reservoir tank to clean and am replacing the radiator today/tomorrow(depending on when the part gets here) any write ups or tips on doing the HG would be appreciated.

 

I can safely say don't remove the VVT gear from the exhaust cam unless you have a set of cam alignment tools. I discovered this the hard way.

And get a torque angle gauge for the head bolts because the tightening sequence calls for both torque and then a certain amount of turning.

 

Like this tool or the locking "block" tool?

http://www.amazon.com/gp/aw/d/B007QE6OF8?cache=cd7b871f7f8b53288e31d97cbe12dc37& pi=SX200_QL40&qid=1408273693&sr=8-1#ref=mp_s_a_1_1

 

That tool is good for getting everything lined up for sure. If you have not removed the VVT gear though, you do not really need it. You can slip the front cam seal off the back side after removing the reluctor wheel from the exhaust cam. Here is a pic of mine. You can see the rear cam seal and the bolt holding the reluctor wheel in place.