So my son ignores the heat sensor and dies on the road 500 miles away. National shop says machine the heads and give it a valve job. This is a decent diagnosis with a compression test? Son learned a $2800 lesson. Sound feasible?

 

Your son should have been more careful but yes this sounds feesible, you ought to be a less harse on him, I don't normally pay alot of attention to that gauge unless I already suspect something might be wrong. If your son is young and this is first thing that he has broken, then I wouldnt be too hard on him.

 

Have a local shop drop a junkyard motor in for half the price.

 

I would buy a head gasket set and a repair manual and repair myself. The only thing you have to do is take the heads to a machine shop to resurface. Total cost looking around $500 tops

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Sounds a little pricey to me, machine shop bill should be less than $800 to rebuild the heads like new...only $200 if they just need to be pressure tested and surfaced, there's no way it's $2000 in parts and time to R&R the heads.

As for the junkyard motor route, you have no idea of the history of that thing and almost every time I see someone do that they end up spending more time and money than they hoped to save in the first place.

I agree, buy him the book and tell him to start ripping it apart.

 

The machine shop says the valves are damaged too. Sound reasonable?@

 

I am not hard on him, I gave him a 99 v6 convertible. He gave it back this summer when he wanted big and bought the 95 z28 convertible. His car and check book blew up, not mine

 

Not sure what this has to do with a technical problem... probably should NOT have been posted.

 

Valves physically damaged from a blown head gasket? No. Valves not sealing? Sure, that's common.

Valves can be damaged beyond salvage by piston to valve contact - bending, or a very poor running condition that leads to oil leaving the guide and wearing out the stem. On engines that have had a very long service life the exhaust valves can have so much pitting on the face that you would have to grind enough off them that you go under the spec for margin thickness.

I don't have the heads in front of me, so obviously this is all speculation...if the engine was overheated bad enough then it warps the head and you can't just surface it, the valve to seat concentricity goes away and you need to fully rebuild the heads.

 

I am trusting a national garage 500 miles away. The car has 74k miles which is low but the documentation supports it. Maybe. Could be higher miles. In a case where it overheated, seized and was towed, they called a blown head with valve damage. You don't sound convincing. Am I on a ride to have my pocket picked?

 

"Don't sound convincing"???? Hopefully you meant "don't sound convinced". You are getting expert advice from one of the most knowledgeable engine builders on this site.

 

If the engine seized that sounds like a blown engine not just a blown head gasket.

 

This is the first we heard the engine seized.... whole different ball game.

 

How long has it been sitting? If the head gasket blown was as bad as you say it was then a water journal could be leaking to more then one cylinder and with water sitting on top of the piston can be very bad. My suggestion would be to remove the head asap or if you must wait atleast fill the plug holes with oil and try rotate the engine by a breaker bar 17mm on the front of crank. Also go ahead and drain all coolant from block and radiator before doing the oil and crank turn as mentioned above.

Also yes thats very high for a head gasket+machine work.. For a common machine shop they would love nothing more then to redo the valves. Its easy for a standard valve job and they want to make that extra money while they are already at the valves. Plus mark up on the parts. My suggestion would be to order the book and parts and fix yourself or atleast shop around for a reasonable repair shop.

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Injuneer is hands down one of the most knowledgeable (if not the most knowledgeable) guys posting technical information on the Internet. I would take his advice over a Chevy dealership any day.

curtismc56:
Start from the beginning on what happened with the car. Could you still turn it on after the overheat? Was there oil on the road? Was there oil in the engine? Can you rotate the engine?

If the car overheated and blew a headgasket you should still be able to freely turn the engine. Maybe even start and run the car a minute or two. These engines drive the valve train using a chain. Pistons rarely meet the valves because of this.

If the engine truly seized, this points to an oil starvation scenario. Warped heads happen with a head gasket failure, not so much damaged valves.

Best bet is to scan in/take picture of the entire quote and upload it to here or photobucket. That way we can see what the shop is thinking, too.