Engine Block Test

[chazzy]

Hi! I have a 1999 Cadillac Deville. Runs great but I got a check coolant message and I checked the coolant and it was low. Same thing happened about four months ago. Car is not running hot. Had a engine block test performed and was told that head bolts were pulling out of block because of aluminum head and was a common problem with the Northstar engine. No blown head gasket. The block test reading was 0.8. What does this mean? All this was done at the dealer and would be about $3,500.00 to fix. Help please.

[JimD]

If this was my car, the first thing I would do is find another dealer, or an independent shop, to diagnose whatever minor coolant leak you might have.

A block test reading of 0.8 (whatever that means) is new terminology on this board. I have not heard about a block test before today.

It sounds like you have a coolant leak somewhere and whoever diagnosed the problem is blowing smoke and trying to confuse or impress you with terminology in an attempt to seperate you from $3,500.

[Ranger]

I'm guessing that .08 is a percentage of exhaust gases present in the coolant, but I'd still get a second opinion. Could just be a cracked radiator side tank or surge tank leaking.

[BigCat83]

That test kit I bought at NAPA a few weeks back is called a "Universal Block Tester".

In my experience bad head gaskets manifest themselves by headbolts pulling out of the block.

Usually the bolts in the rear head pull out first.

If you are concerned that this may be your problem I suggest buying this test kit from NAPA and performing the test yourself.

I paid $50 USD for the kit I bought (and didn't use).

[Cadillac Jim]

The usual formula is for the coolant to get 5 years old and become corrosive. This will cause expensive problems in nearly any engine but especially so in modern engines that have major aluminum components such as intake manifolds, heads, and cylinder blocks. If your coolant has never been changed, or hasn't been changed since 2002 or so, then you are at risk. Most cases of Northstar head gasket issues are traceable to old coolant seeping into the head bolt wells and corrosion eventually causing the head bolts to pull out. The earliest symptom I saw when this happened to me was the car started using coolant.

Any good radiator shop can test your coolant for corrosion resistance (end of life of antifreeze) and combustion gases (evidence of head gasket leakage) in a few minutes, or you can get the kit that BigCat83 shows or a kit of test strips; I found several on a web search lately. For testing one car, it is probably quicker and cheaper to ask a local independent shop to to the test.