Jump to content
SAU Community

Recommended Posts

Hey all My car has just given up on life today and I really need some help to hopefully get close to the cause of it...

I drove it yesterday and it was fine.

I drove it for 15 mins to the mall today and it spewed its guts out in the car park... Its Brown murky water that was coming out from the rear of the engine inlet side, (My coolant was pretty green last time I checked about a week or so ago)

I proceeded to head home hoping it wouldn't overheat much as I live fairly close, but within 5 mins it got up to 110 deg

I quickly pulled into BP and it was sizzling and steaming HEAPS where all the heater hoses are under the inlet manifold next to the block. I then opened the radiator.... Empty... Filled it up with cold water.

Temp gauge said 40 deg...so I started on my way home. 1 minute down the road the temp gauge went up to 110 deg, so I pulled over again. Same thing, sizzling and steaming under the manifold.

But this is the catch, the radiator was still really cold, the top hose was hot, and the bottom hose was cold....

Im hoping its a heater hose seal broken under the pressure and leaking out there, rather than the head gasket, and im guessing my thermostat is stuffed??

Does anyone have any suggestions for the cause?

Also I live in Glen Iris, Melbourne, does anyone know and good skyline mechanics sort of near me.. I know RacePace is really good and Chris is pretty onto it, but Bays water is way to far in this situation...

Thanks guys :)

Link to comment
https://www.sau.com.au/forums/topic/400603-need-some-help-and-suggestions/
Share on other sites

one hose will always be hotter than the other as one hose is have cooled coolant flow through it and one has coolant fresh out of the engine. and given that there is a leak in the system, that will make the problem worse. also if your radiator is somewhat blocked (not totally blocked, but not flowing like a new one, which is a common problem on older cars) then that will make the radiator feel colder than it should

another possible issue is that your water pump is worn out

Water pump was also another possibility that just came to mind also, so maybe that needs looking at, I wish there was a way to test it. Its just weird because the temps rarely go above 76 deg on ecu and its always run fine, then it just did this out of the blue. Water pumps dont just work 1 day and not the next do they?

When I mention the hose and radiator were cold, I mean like chilled cold.. definitely not normal.

Thanks for the reply

i think the first thing is to get the leak sorted and then see what temps do. a leak in the cooling system will cause temps to skyrocket. for example, i've seen plenty of overheating issues caused simply by a dodgy radiator cap.

Yep. Fill up cooling system with water and pressure test, check for leaks. If no leaks are present and it holds pressure then remove thermostat and check opening temp. Replace if necessary.

Retry bleeding cooling system and try again

Today I disconnected the radiator and hoses and flushed it and the block out with heaps of water. Fitted a new thermostat. then filled it all up again.

It bubbled a little but it didn't look anything out of the ordinary. at about 90 deg it started to overflow as it would. so I put the cap on and went for a quick drive around my apartment

It didn't overheat once pressurised on the drive, It got to 90-92 deg (using water) Once home I noticed a constant dribble coming down the gearbox from above the starter motor. I cant see the actual place it was leaking from tho.

Good news is the water pump still works and it was clean water leaking not oily water as suspected earlier, nor was the radiator bubbling or dipstick with any residue. bad news is I cannot see the leak so the manifold will need to come off, Im suspecting a heater hose.

It looks like a bit of a mish to get it off and I don't have too many tools here to even consider the task ahead. Is there anyone recommended for skyline work? I dont want to take it to just any mechanic.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Bit of a pity we don't have good images of the back/front of the PCB ~ that said, I found a YT vid of a teardown to replace dicky clock switches, and got enough of a glimpse to realize this PCB is the front-end to a connected to what I'll call PCBA, and as such this is all digital on this PCB..ergo, battery voltage probably doesn't make an appearance here ; that is, I'd expect them to do something on PCBA wrt power conditioning for the adjustment/display/switch PCB.... ....given what's transpired..ie; some permutation of 12vdc on a 5vdc with or without correct polarity...would explain why the zener said "no" and exploded. The transistor Q5 (M33) is likely to be a digital switching transistor...that is, package has builtin bias resistors to ensure it saturates as soon as base threshold voltage is reached (minimal rise/fall time)....and wrt the question 'what else could've fried?' ....well, I know there's an MCU on this board (display, I/O at a guess), and you hope they isolated it from this scenario...I got my crayons out, it looks a bit like this...   ...not a lot to see, or rather, everything you'd like to see disappears down a via to the other side...base drive for the transistor comes from somewhere else, what this transistor is switching is somewhere else...but the zener circuit is exclusive to all this ~ it's providing a set voltage (current limited by the 1K3 resistor R19)...and disappears somewhere else down the via I marked V out ; if the errant voltage 'jumped' the diode in the millisecond before it exploded, whatever that V out via feeds may have seen a spike... ....I'll just imagine that Q5 was switched off at the time, thus no damage should've been done....but whatever that zener feeds has to be checked... HTH
    • I think Fitmit had some, have a look on there (theyre Australian as well)
    • Hah, fair enough! But if you learn with this one you can drive any other OEM manual. No modern luxury features like auto rev-matching or hillstart assist to give you a false sense of confidence. And a heavy car with not that much torque so it stalls easily. 
    • Actually, I'd say all three are the automatic option. Just the different trim levels. The manual would be RSFS, no? 
×
×
  • Create New...