As far as checking the wiring harness, whoever ends up with it..... Test it using a Time Domain Reflectometer.

For anyone that does not know what it is, wiki has a good description of it.

We have one at work that we use to test for wiring faults in the weapons systems since wiring failure could be catastrophic. Simply using an ohm meter will not tell you if you have faults in the line.

I tested my harness at work with one and luckily no faults after testing.

hope that info is useful.

Jason

 

very impressive guys. glad to know it's finally fixed. I wonder what made the owner stick beside it for so long............?


wait...............I think I know.....

 

now thats a pretty cool name for a tool!

 

Even the name sounds expensive, nevermind reading the description

 

I think I saw one of those last week on Doctor Who...

 

Wow we need an award for the most PIA 951 ever! From new the problem started! I would have thought that at some point he'd have thought to himself...I could have had a V8!

 

seems like when I first joined there was a member with a car that blew HG's on a weekly basis even with a different engine, trying to remember his username. Wonder if he had the same problem, he finally gave up on the car IIRC

 

Very interesting thread thanks for posting Chris and adding color Mike. Having been through a few head gaskets myself (probably like most of us) I've gotten into the habit of assessing coolant pressure almost routinely after hard pulls. Sorry a little off topic but anyone know of a device out there that could be bolted to the cooling system to give peak pressure readings as an early indicator of HG failure? Not trying to replace a proper tune of course. Thx

 

Time Domain Reflectometer.
Sounds related to Blinker Fluid ;-)

 

I thought our cars used a knock sensor to pull timing, and boost. Was that not happening?

 

the defect must have been in that part of the harness...?

 

Pretty much any pressure gauge will work fine. It’s better to use an electronic version instead of a mechanical so you have less risk of leaks. Some of the electronica gauges have a peak recall function.
In fact a boost gauge is a very good choice – it has the right pressure range and it will measure vacuum – and the system should be under partial vacuum when cold – if not then you have a leak somewhere!

 

interesting thought

Must the boost sensor be placed in the expansion tank where there is air or could it be mounted anywhere in the cooling system?
Does the sensor tolerate water?
otherwise you could use a cheap oil pressure gauge but then you miss the vacuum bit

 

If you use a boost gauge you need to mount the sensor in the upper part of the expansion tank. If it’s a moisture sensitive sensor add a couple of small loops of hose before the sensor and it will be OK.

The range on most oil pressure gauges is so high that you barely notice 10 psi of pressure.