Suspected blown head gasket

[Nick S]

Hello, Can anybody help & advise.

I have a 5.7L SBC which I took for a leisurely spin last night and she ran well, however I noticed that as I neared home the temperature started to rise (upto about 90). I got home OK, let it cool down, and checked the expansion tank which appeared to be very low ~ I topped this up to about 3/4 full (I now know this was stupid beyond belief) I then let the engine warm up tonight and after about 10mins ticking over, the temperature gauge shot up and I turned off straight away. I let it cool down and went to start it ~ the engine was very very reluctant to turn over then when it did start a large cloud (I mean large!!!!!) came out of the near side exhaust. Have I done untold damage or what? Any assistance greatfully received, I have limited mechanical knowledge, so if you can respond in words of one syllable please, Nick.

[mike huddart]

Dear Nick, it does sound like gasket trouble but having said that, 90 degrees isnt that hot. Gaskets dont just blow for the fun of it, though, there is a .reason for everything. Do you know the history of the engine? Has it got iron or alloy heads? Iron, of later years can be prone to cracking, but dont get too exited, most things are cheap for Chevys......Regards Mike

[Nick S]

Originally Posted by mike huddart

Dear Nick, it does sound like gasket trouble but having said that, 90 degrees isnt that hot. Gaskets dont just blow for the fun of it, though, there is a .reason for everything. Do you know the history of the engine? Has it got iron or alloy heads? Iron, of later years can be prone to cracking, but dont get too exited, most things are cheap for Chevys......Regards Mike

Mike,

Called it best in the garage tonight ~ getting grumpier by the minute. Will check out the head situation tomorrow and let you know. I have looked at the engine number tonight and I think it is 57LG SGI, is this right and is there a way I can find out the head type from this.

[rich]

Hi nick, the No. you have found tells you its a 5.7 L [dunno what the letters mean, maybe Mike does]

This link should help you find your casting No.
or it maybe on your V5 or VIN plate.

However you may well have aftermarket heads so this will not identify them, have a look around the head for No.s or names, and you should be able to see if they are ali or cast iron


HTH

[jrv8]

Hi,

Try the heads with a magnet to see if they're cast iron or alloy.

Jim

[mike huddart]

Dear Mr Grumps, all that referance tells you is its a fairly late engine, certainly mid 80,s on. The colour of the heads should give you a clue..... silvery for ally. Something horrid, like the rest of the engine, for iron. A lot easier than messing about with magnets. Joking appart, I think you are going to have to bite the bullet and take the heads off anyway so you can sort out what you have or havn,t got then. Get yourself a large Scotch and forget it fo tonight, its only a lump of metal afterall...... Regards Mike

[Miket]

Originally Posted by mike huddart

Its only a lump of metal after all...... Regards Mike

Yes but without the so called lumps of metal, you would be out of a job.

[mike huddart]

Originally Posted by Miket

Yes but without the so called lumps of metal, you would be out of a job.

After 40 years,I wish........Mike

[mike huddart]

Originally Posted by mike huddart

After 40 years,I wish........Mike

Sorry, make that 45, I knew I,d been doing this too long!

[wilf]

Nick - a little advice - whatever it is, don't tell the wife!