Thank you to the forum

[4bye4]

I have a engine related business and we have had for the past six weeks a GM motor that kept stopping and bringing up strange fault codes. The fault codes were indicating high temp in cylinder heads although the radiator was still cool enough to touch. Whilst today boffins from the machine manufacturer and engine manufacturer were busy swapping emails, I remembered reading several posts here about air locks in engines causing the motor to go into limp mode. Anyway to cut a long one short, removed the radiator cap, stuck in a cut down coke bottle started motor. After about 5 mins got a big burp and temperatures stabilised. Restarted by the experts several times this afternoon and all good. Thanks to people on the forum who posted info on this problem. Now the equipment manufacturing boffins can pack up there diagnostic computers and go home. Thanks forum members.

[nissannewby]

I'm surprised that it wasn't something they checked initially. I bet they were "technicians" lol.

[4bye4]

Their thinking was from the start, the temp readings are up but the water is cool - must be the sensor or the Engine Management System. I should mention that these people were not at my place, they send boxes and computers to me, I did the tests as requested then emailed the results which were then emailed to the USA who responded with more tests to be done and so on. Two Engine Management Systems were sent which had to be plugged in and remapped then tested. Same for sensors. Email hook up, telephone hookups and messages everywhere. Only two of these motors in Australia. One here in Perth and one in Queensland. The manufacturers are also very careful as to what data they share. Trying to get pin out details or voltage levels was not easy.

[Stropp]

Yes always amazes me these so called experts look for the technical problem first rather than going for the simple stuff to check.

[Bush Ranger]

This reminded me of the V6 motors in VN Commodores, where the heads were higher than the radiator filler. In which you had to bleed the system to get the air out of the system.

[4bye4]

OK an update on this motor. After the air lock problem, there appeared a few more issues. One was shutting down every so often and could not be restarted. No fault codes in Engine Management System. Tests indicated that it was running out of fuel, but there was always fuel in the lines. Best test was to disconnect the fuel line where it entered the injectors and get a shower. Also the spark was failing now and then. Anyway to cut to the chase, the fault eventually turned out to be bad continuity in the fuse block for the motor.
So why do I write this booring saga about a non Patrol engine. Well the fuse block and fuses are all good quality. The fault was due to build up of crap on the blades. remove each fuse and clean the blades and replace them fixed the issue. I have seen on this forum quite a few time members with strange electrical problems, and given that we tend to drive through water, mud and everything else, this is something I think is worth remembering. Can of WD40 os similar and check the blades on the fuses are clean, especially when the fuse is "good" but the fault is still there. Even taking the fuses out and putting them back in again will help clean the blades and the rails they slide into.

[the evil twin]

Great reminder, cobber

Curious how dropping a spanner on a battery can weld steel but the same battery can't jump a couple of microns of corrosion on a fuse eh.

In my long but undistinguished military career I used to love it when the Pilot would bring a C130 home to Richmond with a fault along the lines of
"After 5 hours flying at 36,000 feet with an outside airtemp of -50 degrees whenever we did a left turn and switched on the oven to cook a frozen meal at the same time the #3 engine fuel pressure would jump 5 PSI for 1/2 a second and only does it in the northern hemisphere with flight cruise power settings after filling up with JP4 fuel in Guam"

Thats why they don't give RAAF techo's firearms... we don't have enough Pilots

[threedogs]

Thats my number one thing for water/radiator related problems especially if dual fuel.
Park nose up somewhere and invert the coke bottle to raise the fill point.
Great tip on the fuses to, might be worth picking them out and giving them a clean
next time I wash the engine bay thanks

[Cuppa]

The fault was due to build up of crap on the blades. remove each fuse and clean the blades and replace them fixed the issue. I have seen on this forum quite a few time members with strange electrical problems, and given that we tend to drive through water, mud and everything else, this is something I think is worth remembering.

http://caravanandmotorhomebooks.com/...s-in-caravans/

[rusty_nail]

Thats my number one thing for water/radiator related problems especially if dual fuel.
Park nose up somewhere and invert the coke bottle to raise the fill point.
Great tip on the fuses to, might be worth picking them out and giving them a clean
next time I wash the engine bay thanks

Also cleaning the maf and disconnecting the battery for 23.45 hours tips I've learned from this forum, it usually is the solution to most problems =D