blown head gasket?

[marksar]

Hey guys got a '96 Mystic with about 120k on the clock. I needed to change my oil and normally I run Shaffers synthetic blend race oil and have never had a problem. I couldnt get a hold of my suplier so I went to O'reillys and decided I was going to try Quaker states new sythetic blend "high RPM" motor oil. Almost immediately after the change I noticed an increase in water temp, before my car was on the "R" on "normal" now it was between the "M" and the "A". Drove it for about two weeks and it progressively got worse till the temp was constantly on the "L". I flushed out my coolant system after replacing my thermostat and finding a piece of black plastic about 1" X 3/4" down by the the thermostat but found nothing else, tried driving the car and it still was runing at the same temp. I found a supplier for Shaffer oil about 50 miles away so I got some and changed it out. I went for a test drive and when I got back water was blowing out form under the radiator cap. I let it cool off filled it back up and let it run for a few minutes with no overheating issues. As soon as you give it gas though large air bubles start comming into the water reservoir. Could this be anything but a blown head gasket?:dw:

 

[na svt]

Pull the plugs and look for one or two that look very clean.

 

[STAMPEDE3]

You did burp the system after the flush didn't you?

On the stock temp gauge the difference from the "R" to the "L" is about 15-20deg. Hows the weather been? hotter the last few days?

But as NA said, check the plugs.

 

[marksar]

At the time it was hotter than hell about 106 degrees avg. for a couple of weeks, and I did burp the system while it was sitting. Like I said it will sit and have a normal temp while at idle, but as soon as I drive it the temp climbs it doesnt matter how hot it is outside, it could be first thing in the morning. I got it in storage about 40 minutes away, so I cant look at the plugs now but I will as soon as I get the chance.

 

[marksar]

Ok I pulled all the plugs and all of them look the same. They are only about 3-4 mos. old so they arent filthy to begin with but none of them were any cleaner than the other ones.... any ideas? Started to do a compression test but the f&*#n adapter came off on the second cylinder so I'll have to get a reverse thread bolt to get it back out later when stores are open.:bash:

 

[marksar]

Hello... Anyone?

 

[Quadcammer]

what weight of oil did you run?

 

[P49Y-CY]

i'm a little confused - you changed the oil, did nothing else, and then it ran hotter (but didn't boil over)?

then you flushed the cooling system and it boiled over?

 

[COBRASVT]

Yes...you either have a blown head gasket or a cracked head.

I'm having the same issues....exactly. I reasearched the crap out of this and came to the conclusion above.
I don't have fluid in the oil...nothing on the plugs...nothing in the radiator....but when I rev it past 4k, the temps quickly rise and fluid blows out of the overflow.

That's the classic "crack in the head" symptoms or a minor break in the head gasket. When the pressures inside the cylinder rises, it squeezes out the small crack or break in the gasket. That pressure is put into the water system causing the blow out of the overflow and of course, a rise in temps.

You can have the rad pressure tested, but it takes a special adaptor, so you have to have someone that has that adaptor do it.

I have yet to take mine in, but I'm pretty sure I've diagnosed it correctly.

Most guys are telling me the engine has to come out, etc. Prolly around a $2k fix depending on wether you repair repair / replace the head or if it's really only a gasket.

Good luck...we're both in the same boat.