All,

There’s a lot of great help on these forums, please give me your advice and time - i would really appreciate it, I’m getting my butt kicked here by my S70.

Short Story:
98 S70 bought used - Ran fine. One day when pulling into my subdivision the car started screaming HOT, coolant reservoir overflowing. I checked the little stuff: Coolant lines for leaks, coolant reservoir, thermostat, ECT. Listened to the advice of my father in law too quickly and just started tearing it apart thinking it was the head gasket without doing any further investigation.

Put everything back together.....

And still overheating, coolant reservoir still overflowing. Also there was a "pop" noise coming from the Cylinder 5 area of the engine like "popcorn". And I was getting a Cylinder 5 misfire code. I assumed i had done something wrong with the Cams/timing belt and caused myself some bent valves. Even with the "popping" the car still ran so i decided to focus on the overheating problem: i flushed the system/radiator about 10 times! And the car would run fine with no overheating, but as I would wrap up the day and let the car sit for the night/2 days it seemed like the radiator would get all "clocked" up again. When i would drain the radiator upon flushing it would be that milkshake nasty mix, but when i would drain/flush the block it was clear water.

I thought i would have a crack in my head/block causing this mixing/overheating/and misfire. So yesterday I took the head back off of the car and inspected it. No obvious signs of cracked head/block/ or bent valves! When i drained the oil - the oil was clean (no water mixed in with it) but as I stated above the coolant still has oil in it.

After reading a lot last night I keep seeing people discussing a bad radiator? How oil lines go thru the radiator and could rupture? I tried finding some information on this and so far no luck.

Is this possible? Could this have been my problem the entire time and I’ve been messing with the head for no reason? What about the "popcorn" noise?

I have attached a picture of the inlet for the radiator (as you can see its all full of that junk) and i have attached a picture of the top of the block after i took the head off. The reason i attached this picture is because as you can see I have all that milkshake crap on top of the block. Is that a sign of anything (I.E Crack that I’m not seeing) or could the water jackets have just carried that from the radiator?

Guys, PLEASE HELP! I’m dying over here getting my butt kicked by my car!

 

Clean up the head and put on a new gasket. I'm thinking the poping noise you are hearing is air escaping from the head where the gasket is bad. Take the head to a machine shop and have them check to see if if there are any cracks or possible warping from over heating. Make sure you follow the correct procedure when replacing the head gasket and use gasket sealer as specified. I have never done this procedure but I did watch a mechanic work on a S80 head gasket. You need to use new bolts on the head to secure it to the block since they strech when you torque them. Now replace the radiator with a new one. I seem to remember that on the 1998 XC70 the oil cooler for the engine is built into the radiator and it is possible for the oil to mix with the cooling system when the radiator goes bad (you need to check on this). A new radiator will fix that problem. Also change the PCV vent system while you have everything apart (you can see it in the picture of the engine block). Sorry about all the trouble you have gone through but you probably will have a decent running engine when all is done.

 

It's a brand new gasket - you think it would be bad already?

Do you think it could be a bad lifter? Do they go bad? Stick, ECT? And a lifter not lifting properly causes that "popping" noise?

Thanks for your input so far! i really appreciate it!

 

Once you torque down and seal a head gasket, it's no longer new. I'd get another new one. To much heat, pressure and work to chance a used gasket.

As for the lifter, they do go bad but they usually make a ticking noise. It's normal for them to stick a little, the owners manual even says so. I'm thinking you had some air problem or something that was causing air to escape when you put it back together. If the car over heated, you should take the head to a machine shop to have them check to make sure it's 100% flat. They will machine it if it needs to be fixed. There is really no way around that.

Did you replace the water pump? That would be the 2nd thing I would check if my car was over heating. The radiator would be 3rd. Thermostat 1st.

 

Thanks RSPI,

Thermostat is New, Water pump i dont see any leaks. Radiator as you see in the first post is my angle here because of all the Oil in there.

You mentioned that lifters will cause a ticking sound - have you ever heard of the "popping" noise that i'm referring to? It sounds like its coming from the top of the engine (head) when i listen close, also sounds like its coming from the Cylinder 5 "area" where i am also getting a missfire code for.

I am going to bring the head to a machine shop again next week. Have them inspect all the valves and pressure test for leaks. Also like you mentioned have them machine the head if needed to ensure 100% flat. I will order a new gasket tonight.

 

JeepFire, you're doing the right thing. Did you happen to do a compression test before you dug into things? I'd hate for you to be doing all that work on a worn out motor.

Besides that, I have never heard a poping noise. My guess is that the head gasket wasn't 100% sealed and the piston was poping air or something past the gasket.

Now the water pump... I had a 960 that was getting hot and the water pump was broken.

Dang perpeller was just lying in the block.

 

Let me know that you seen the water pump pic.

 

Got the picture! Is there a way to inspect the water pump to see if its bad? Looking for leaks at this point is out of the picture, I know in can rotate it to see if it spins easily, ect - should i take it apart and inspect it ?

 

The only time I can remember hearing a popping noise coming from a motor was when the intake manifold (plenum?) on my mother's BMW 530i failed (split at the seam) and it would pop as the metal expanded and allowed air to escape. I think this is the same situation only it's happening at the head to block connection where the head gasket is located. Do a compression test to make sure all the other cylinders show good even compression. Next pull the head and bring it to a machine shop and make sure none of the valves are bent and the head is still flat. Replace the water pump, radiator, and themostat. When you go to put the head back on the car make sure you torque each of the a little bit at a time (there is a pattern to follow and amount to torque each bolt). Never torque a single bolt more than a certain amount (whatever the rule is) or you will warp the head. I believe you should be using some sort of sealant when replacing the head gasket so you should let it dry over night (chime in here other mechanics).