Technican: He would need to do a compression test to determine if the head gasket was blown. If he hasn't, the test needs to be done and followed up with a leak down test to confirm head gasket failure.
So yes, if he hasn't done proper troubleshooting it could very well be something else.
Owner: yes he did the compression test and confirmed that there was no compression.
Technican: Likely is head gasket failure if the camshaft is turning (timing chain has not broken or jumped).
Two adjacent cylinders that have equally low compression is a tell tale sign of head gasket failure.
A remote possibility is when oil that is to heavy of a weight is used. When it gets cold thick oil can hold the valves slightly open causing a no start. This is rare and would be resovled once the temperature rises.
I don't notice any 'alarms' indicating your mechanic is trying to 'take you'.
Technican: I was notified of your disapproval of the payment process. I would like you to know I'm still available to answer any questions you have without the incentive of a cash payment.
I did a technical service bulltetin (tsb) search on your auto and nothing came up related to your problem. Although when I was working with another nissan model I stumbled upon a tsb involving a no compression/no start. The cause was the lifters holding open the valves. You may wish to advise your mechanic not to overlook this possibility. The leak down test i mentioned will pinpoint where the problem is.
- A leak down test is when compressed air is introduced into individual cylinders via the spark plug hole. When a cylinder won't hold compression (as with yours) the air escapes. It's easy to locate an air leak, whether it's out the intake or exhaust(valve problem), head gasket, or past the piston.
If you have no compression AND no leak, the valves are not opening properly (camshaft/valvetrain problem).
Owner: Thank you for your response. They did the leak down test and said that they were leaking air from one into another...They seem to think that there was no antifreeze (may have leaked out) and when it turned cold the other night it caused something to crack. Does this sound feasible to you?
Technican: If the antifreeze had been leaking and was replaced with water, and the temperature dropped below freezing it certainly can freeze and cause a crack. What do you mean by turned cold? A friend called from florida and said he was freezing when it turned cold there (45 degrees F). Where I'm from it hit minus 1 last week (this low of a temp can cause freezing and cracking, while the 45 degrees will have no effect).
If the coolant is missing they should have pressurized the cooling system and checked for leaks. Inspected the spark plugs, if coolant had been leaking past the head gasket and into the cylinder it would discolor the plug and be easy to spot. Had you noticed any excessive white smoke from the exhaust? You already said it wasn't overheating so you may have had a small leak, this could be internally (head gasket) or externally. Your mechanic should be able to determine this.
Also, you don't need to be overheating to blow a head gasket. Although overheating an engine is asking for the gasket blow, head crack, cylinder wall crack, etc.
Reply back, and let me know if this will be a home repair (I can assist you with free online intructions if your unaware they exist), or will a professional do the repair?
Owner: A professional is doing the repair. However, thank you for the offer. By "turned cold" I meant from 60 degrees to 20 overnight. The car didn't move, so we saw no smoke while it was running. Just couldnt start the next morning after the hard freeze. Everything had been fine before then. The mechanic did say the spark plugs were all gunked up with something which made him think it was antifreeze.
Technican: "That much of a temp change could effect a weak gasket that was on it's way out.
Do you generally distrust this mechanic or think he is unqualified? I know enough of them that fit this description. One safeguard is to request to see all the old parts (in ny the customer has legal rights to the old parts).
60 degrees would be nice, hasn't been above freezing in about two weeks here.
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