Overheated (blocked waterway pics)

projectgtir

Member
Looks like i may found the reason my car overheated .
I was driving the car hard but temps were fine .
Got stuck in traffic jam and I switched the engine off then back on 5 seconds later .

Water temp went straight up to 3/4 of the scale and i knew something was wrong as the car started to rev on its own upto 2000rpm then back down to idle speed then back up .

As it was impossible to drive I pulled over and lifted the bonnet . I could hear the rad/water pipes bubbling and the expansion bottle was full to the brim . I turned the rad cap slowly to to ease the pressure and let it cool before nursing it home .

The strange reving on its own had now gone . Next day change the coolant and warmed it up ,sounded fine and fans came in when they should . But after checking the oil cap I had the dredded mayo .
 

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red reading

Active Member
The water gallies are not anywhere near blocked enough to cause overheating, i think your problem lies elsewhere or the h/gasket was the problem.
 

projectgtir

Member
I was thinking the core of the block was being denied cooling . I see your point though there are plenty of other water lines . Maybe it contributed but wasn't the cause.
What would I look for with the old hg.
It seemed ok.
 

projectgtir

Member
I've got the water pump off ,apart from rusty blades nothing seems wrong going to change it regardless . The crank pulley had separated when this overheating had occured.
Could this have been a factor , as there was always a squealing sound on start up no matter how much I tensioned the alternator belt it would disappear after a while.
 

projectgtir

Member
Now you mention that fast guy I fitted a new one 2weeks before this happend maybe it's faulty . It wasn't from Nissan .
 

PobodY

Moderators
Staff member
there was always a squealing sound on start up no matter how much I tensioned the alternator belt it would disappear after a while.
On mine, that was the sign that the alternator was on the way out. - It would squeal quite often, but with a newer unit in it doesn't (even without tightening the belts at all).

Maybe something on that belt is shot... like the water pump?
 

projectgtir

Member
Yes the crank pulley was fooked when the overheating happened I could spin the outer part where the alternator belt sits on by hand while the inner keyed part stayed still. It would grip eventually . This would maybe explain the squealing on start
 

stumo

Active Member
Yes the crank pulley was fooked when the overheating happened I could spin the outer part where the alternator belt sits on by hand while the inner keyed part stayed still. It would grip eventually . This would maybe explain the squealing on start
So you knew the pulley was knackered yet you still drove it?

FFS, get a BIG knife and cut your balls off, you shouldn't be allowed to have kids.........
 

projectgtir

Member
Nope , never knew until after when I came to find Tdc the marks were nowhere near where they should of been.
Just to clarify the overheating happened about 3 months ago since then I had the head rebuilt skimmed etc. Then bought water pump anyway . While I was waiting for gaskets From Nissan went to get Tdc but marks never lined up.

Then I posted on here about this and I was informed of the crank pulley separating .
Bought this from Nissan along with seal and bolt etc . This is now fitted and the marks line up now.
So looks like it was just a matter of time before it overheated due to the circumstances. Once I've refitted the head the car should be alot better to drive.

I also had a problem where the car would hesitate very badly once properly warmed up . I'm hoping they are now solved also.
 

projectgtir

Member
£130 for the pulley and £5 for the seal. Also brought new keyway for £1 and there is also a metal ring at the back of the seal which acts as a face . That was £3.
Not that bad really when aftermarket pulleys ones are around the £100 Mark .
 

geoff pine

Well-Known Member
£130 for the pulley and £5 for the seal. Also brought new keyway for £1 and there is also a metal ring at the back of the seal which acts as a face . That was £3.
Not that bad really when aftermarket pulleys ones are around the £100 Mark .
Bloody amazing for the pulley i was quoted £167+ vat from Nissan which i thought was well over the top. I bought two from Eric's for $150 each postage was a bit of a killer though .
 

projectgtir

Member
Bloody amazing for the pulley i was quoted £167+ vat from Nissan which i thought was well over the top. I bought two from Eric's for $150 each postage was a bit of a killer though .
They must have come down in price .Some things go up and down .

I brought one handbrake cable before christmas these are £75 a side . 12 months ago they were £50.
 

stumo

Active Member
I'll let you off using the big knife LOLz

Always use a Nissan thermostst, they are reliable, not cheap tho'.

If your block has that much crap in it, check your radiator when it's hot for cold spots. After 20 years they can be blocked up.
 
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