Overheating Auto R33

[Mr_G]

Hi All,

Looking to seek some knowledge on an overheating problem with an Auto R33.

There was lots of rust in the system, had to flush the radiator numerous times and also replaced the thermostat whilst I was at it. After flushing the whole system out and putting in the new thermostat, the water still boils. Im not too sure how long the rusty water has been sitting in the radiator, but appears to be a long time. Im not too sure if it would be a head gasket either?

Even with the new thermostat, the water tends to spit out intermitently, rather than flowing like a river. This is only when the engine is reved and leaving the top hose off to check. There is no white smoke coming out the exhaust so I dont think it is a head gasket. The only things I can think of are;

- Water pump

- Radiator possibly clogged from all the rust

- Head gasket

Hopefully someone can shed some light. Im sure it is one of those 3, hopefully number 2!

Many thanks,

Jason

[rgr34]

you have done the right thing so far, id go ahead and get the raidiator core recoed or cleaned professionally no doubt it is blocked.... also change the radiator cap....

[mad082]

yeah as above, start with the radiator. if the coolant was rusty looking then you can pretty much garantee that that radiator is going to be a bit blocked, and just normal flushing won't do a thing to solve this

[Mr_G]

Thanks Guys.

If the car isnt blowing any smoke, the oil looks fine, whats the probability it is a head gasket?

The temp is fine with the top hose off as im constantly running water through the system when im flushing, i.e not presurised. When I put the cap on, reconnect the top hose and take it for a drive, then the heat goes up and you can hear the overflow bubble.

So the blocked radiator is more than likely the problem?

Jason

[mad082]

if it was the headgasket you would at least get some sort of smokey haze when starting the car after it had been sitting for a while, so i would leave it as being the last thing on the list to look at.

i would start with the radiator as even if it isn't the only cause, it is probably going to be a major cause and getting it sorted would be a good thing either way. i would also get a new radiator cap just to see what that does. they are pretty cheap so if it doesn't change things there it isn't much of a loss. just make sure that you get a cap rated to the same pressure. i'm not a fan of using caps with higher pressures than standard as it can cause issues in other areas.

also, this may sound a bit silly, but you are putting coolant back in the system aren't you? you aren't just filling it up with just water? if you are, then get your radiator cleaned (as it will probably be rusting up pretty quickly now) and then get some proper coolant.

[Mr_G]

^ Thanks,

I ended up putting in a new radiator, got it all hooked up and just running water through the system. This was a weird problem though, since pulling the radiator out and putting the new one in, the auto transmission now has issues, ie feels like it just slips when trying to drive? Car barely moves, engine revs but car barely gets anywhere, feels like a really bad slipping clutch in a manual, without the smell.

Note that the radiator actually has 2 extra lines that run into the bottom because its auto. Not entirely sure whether this has had any effect?

On a side note, the engine still overheating

Any help would be appreciated.

[Bozz]

Those two extra lines are the auto transmission fluid cooler.

If you dont hook them up, the auto will pump out all the trans fluid within a minute of starting the car, you'd know about it.

If the lines aren't in the new radiator and you've blocked them up, I'd say your auto isn't getting fluid and the cause of those symptoms.

If the lines are leaking and coolant is getting into the auto, it looks like its manual conversion time - chances are the auto will be well and truly screwed by now.

It could be something as simple as the trans has lost some fluid and is now low, while the radiator was being changed. Check trans fluid level.

[Mr_G]

Those two extra lines are the auto transmission fluid cooler.

If you dont hook them up, the auto will pump out all the trans fluid within a minute of starting the car, you'd know about it.

If the lines aren't in the new radiator and you've blocked them up, I'd say your auto isn't getting fluid and the cause of those symptoms.

If the lines are leaking and coolant is getting into the auto, it looks like its manual conversion time - chances are the auto will be well and truly screwed by now.

It could be something as simple as the trans has lost some fluid and is now low, while the radiator was being changed. Check trans fluid level.

Thanks Bozz,

I think it will be the transmission fluid as I did start the car without the radiator connected just to move it, probably explains the red stuff on the driveway! Grrr... Is it easy to top up the transmission fluid?

Jason

[Bozz]

I dont know how Nissan auto's work, hopefully someone can confirm/update the following comments. This is a generic process for most autos as long as there is a dipstick to measure fluid level.

Also be sure which fluid is going in, whether its the usual Dexron III or something else like TQ95 or whatever. Most likely Dexron III but dont chance it or it could cost you big dollars if you get it wrong.

There should be a dipstick to check the auto's fluid level near the firewall. Pull out the dipstick (it will be long) and wipe it clean

Reinsert all the way and remove it again. Check fluid level, it may have writing like Hot and Cold (or H C etc) which is the level when the transmission is hot or cold. There should be a level marker, usually crosshatched, the bottom of the crosshatch is the minimum level, the top of the crosshatch is the maximum level.

With the engine off, top up the trans fluid to the minimum level, let it sit for a minute and re-check the levels. Once it settles at the bottom, start the motor, firmly apply the handbrake, put your foot on the brake and move the selector lever through all the gears. Let it sit in each gear for 5 seconds or so.

Turn off the motor and check levels again. Get it to the minimum marker.

Start the motor, foot on brake and cycle through all the gears again.

Put it into park, leave the engine running and check the level. Now top it up to the maximum (or full or whatever) marker on the dipstick. It'll be a small amount of fluid, perhaps 1 litre from the minimum to maximum mark. Do not overfill it!

Check again - the fluid level is usually checked while the engine is idling. Once it settles at the maximum point, it should be good to go.