Jump to content
SAU Community

Help ... V35 250gt Overheating Big Time !

Fanta R33GTR
 Share

Recommended Posts

Fanta R33GTR Contributor

Fanta R33GTR

Posted
Posted (edited)

My 250gtm is overheating .. .help.

this is what happens.

when driving with load on the engine (e.g air con on or going up long hills) , the temp get up to about 3/4 way. Normally sits at around just below 1/2 way. Under normal driving without the air con on and flat motoway / city driving it stays at normal temp. You can sit on idle without overheating.

Doesn't seem to be related to the air con as I can replicate the overheating by driving around with the brakes slightly on to simulate load.

I've had the car 2 years.

Engines done 55K and been serviced regularly

It just had a full service a few weeks before the problem occured. New oil and oil filter and air filter etc.

Didn't touch the cooling system. Oil is the same thats been used for last two years - magnatec and level is good.

I flushed coolant after the over heating problem occurred.

My wife got it so hot going up hill with 5 ppl in the car that the coolant overheated started to pour out steam from the top of the expansion/reserviour tank.

checked all the fuses and coolant pipes. no leaks.

this 250gt has no additional radiator fan part from the main one attached to the engine.

what could it be ?

Edited by Fanta R33GTR
Link to comment
https://www.sau.com.au/forums/topic/299830-help-v35-250gt-overheating-big-time/
Share on other sites
GoldV35 Enthusiast

GoldV35

Posted
Posted (edited)

I think its unlikely its the thermostat, because the only 2 faulty conditions it could have are either stuck open or stuck closed. If it was stuck closed, then you wouldn't get boiling coolant steaming out of the overflow tank, as it only gets coolant from the radiator. If it was stuck open, then it definitely wouldn't overheat.

Could also of course be the thermo fan, but I wouldn't have thought it would be an issue if you are driving, as that usually has enough airflow to cool without the fan.

I'm leaning more towards a water pump issue, either way, take it to a mechanic asap, then let us know if I got it right :rofl:

Edited by GoldV35
Fanta R33GTR Contributor

Fanta R33GTR

Posted
  • Author
Posted
I would be taking it to the mechanic that services ur car asap. Might be a faulty thermostat. have u checked ur radiator fan is coming on?

this car has no additional fans. Only the one big one attached to the engine. I know some cars also have another one on front of the air con radiator, but this car only has the one.

Fanta R33GTR Contributor

Fanta R33GTR

Posted
  • Author
Posted
I think its unlikely its the thermostat, because the only 2 faulty conditions it could have are either stuck open or stuck closed. If it was stuck closed, then you wouldn't get boiling coolant steaming out of the overflow tank, as it only gets coolant from the radiator. If it was stuck open, then it definitely wouldn't overheat.

Could also of course be the thermo fan, but I wouldn't have thought it would be an issue if you are driving, as that usually has enough airflow to cool without the fan.

I'm leaning more towards a water pump issue, either way, take it to a mechanic asap, then let us know if I got it right :)

is there a easy way to test if to see if it is the pump at fault ?

The Max Mentor

The Max

Posted
Posted
is there a easy way to test if to see if it is the pump at fault ?

From a cold start (so you don't get hot coolant blowing up in your face), take the radiator cap off and check if you can see the water flowing. Gradually accelerate and the water flow should increase with it. Check for any water dripping from the engine which would indicate any leaks from the water pump itself or possibly a blown welsh plug.

If your radiator fan isn't working, your car will overheat at idle after about 5 - 10 min and you'll know about it.

Worst case scenario, could be a blown head gasket. Happened in my old Maxima like that once.

zei20l Grand Master

zei20l

Posted
Posted

its probably easier to check/change the thermostat than stuff around with the water pump. which will probably whine if its a problem

if your thermostat was stuck closed, it CAN spit out the overflow tank as the pressure build up forces the coolant out anywhere it can

but before doing this, dump all the coolant out, and refill the system and bleed it properly! there will be a bleed point on one of the flanges. it could be you just have some air stuck in the system. turn on the heater (on full) and run it like that for a while too.

Fanta R33GTR Contributor

Fanta R33GTR

Posted
  • Author
Posted (edited)

yeah...... it has a 3 year warranty from the dealer, so I dropped it into them and will let them sort it out. Not much i can do.

Thanks

Edited by Fanta R33GTR
  • 10 months later...
wabbo69 Enthusiast

wabbo69

Posted
Posted
yeah...... it has a 3 year warranty from the dealer, so I dropped it into them and will let them sort it out. Not much i can do.

Thanks

Is it fixed yet? and if so what was the problem please?

  • 3 years later...
scotty nm35 Grand Master

scotty nm35

Posted
Posted

The cooling system probably needs to be bled correctly, it is quite difficult to get all the air out. There are a few threads on the subject, here and in the Stagea section for M35's

If it continues or reoccurs, perhaps there isn't enough anti boil coolant in the system, and the water is flash boiling in the head and around the bore. (these run 95-100 degrees on a cold day) Drain and fill with the recommended coolant percentages and re-bleed a few times once it's cold through the rear bleed point only. Obviously you would be checking the thermostats operation while the coolant is dropped, by testing it in a pot of water on the boil, and replacing the radiator cap, just in case.

If you still have issues, you could have a blown head gasket... I have seen it a few times. :/

  • 4 years later...
Jermaine James Rookie

Jermaine James

Posted
Posted

I just recently changed my high pressure pump and this problem started a week ago when it blew a hole on the top tank of the radiator. The engine runs for 5 minutes then coolant starts coming back as the water pressure builds up. It even cracked my radiator and was sparing the water from there. I just changed the radiator because of that.

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • LegendGTR
      EFR7670 exhaust selection RB26

      By LegendGTR · Posted

      I'm looking for some real world experiences/feed back from anyone who has personally ran a EFR7670 with a 1.05 exhaust housing or a .83 I'm leaning towards the .83 because its a street car used mostly for spirited driving in the canyons roads. I"m not looking for big numbers on paper. I want a responsive powerband that will be very linear to 8000 rpm. I dont mind if power remains somewhat flat but dont want power to drop off on top. The turbo I've purchased is a 1.05, although the mounting flange T3 vs T4 and internal vs external waste gates are different on both housings, I not concern about swapping parts or making fabrication mods to get what I want. Based on some of the research I've done with chat gpt, the 1.05 housing seems to be the way to go with slightly more lag and future proofing for more mods but recommends .83 for best response/street car setup. AI doesn't have the same emotions as real people driving a GTR so I think you guys will be able to give me better feed back 😀   
    • PranK
      Stock Airbox and Snorkle for RWC - VIC west

      By PranK · Posted

      Surely somebody has one in VIC. Have you asked at any shops?  Is this the yearly inspection or did you get a canary?
    • PranK
      Duncan's V37.......race car?

      By PranK · Posted

      This is where I share pain with you, @Duncan. The move to change so many cooling system pieces to plastic is a killer! Plastic end tanks and a few plastic hose flanges on my car's fail after so little time.  Curious about the need for a bigger rad, is that just for long sessions in the summer or because the car generally needs more cooling?
    • Duncan
      7 Speed Auto transmission fluid change (Skyline, Q50, Q60, Fuga, Q70, A62 Titan and probably heaps of others including Navara...)

      By Duncan · Posted

      So, that is it! It is a pretty expensive process with the ATF costing 50-100 per 5 litres, and a mechanic will probably charge plenty because they don't want to do it. Still, considering how dirty my fluid was at 120,000klm I think it would be worth doing more like every 80,000 to keep the trans happy, they are very expensive to replace. The job is not that hard if you have the specialist tools so you can save a bit of money and do it yourself!
    • Duncan
      7 Speed Auto transmission fluid change (Skyline, Q50, Q60, Fuga, Q70, A62 Titan and probably heaps of others including Navara...)

      By Duncan · Posted

      OK, onto filling. So I don't really have any pics, but will describe the process as best I can. The USDM workshop manual also covers it from TM-285 onwards. First, make sure the drain plug (17mm) is snug. Not too tight yet because it is coming off again. Note it does have a copper washer that you could replace or anneal (heat up with a blow torch) to seal nicely. Remove the fill plug, which has an inhex (I think it was 6mm but didn't check). Then, screw in the fill fitting, making sure it has a suitable o-ring (mine came without but I think it is meant to be supplied). It is important that you only screw it in hand tight. I didn't get a good pic of it, but the fill plug leads to a tube about 70mm long inside the transmission. This sets the factory level for fluid in the trans (above the join line for the pan!) and will take about 3l to fill. You then need to connect your fluid pump to the fitting via a hose, and pump in whatever amount of fluid you removed (maybe 3 litres, in my case 7 litres). If you put in more than 3l, it will spill out when you remove the fitting, so do quickly and with a drain pan underneath. Once you have pumped in the required amount of clean ATF, you start the engine and run it for 3 minutes to let the fluid circulate. Don't run it longer and if possible check the fluid temp is under 40oC (Ecutek shows Auto Trans Fluid temp now, or you could use an infrared temp gun on the bottom of the pan). The manual stresses the bit about fluid temperature because it expands when hot an might result in an underfil. So from here, the factory manual says to do the "spill and fill" again, and I did. That is, put an oil pan under the drain plug and undo it with a 17mm spanner, then watch your expensive fluid fall back out again, you should get about 3 litres.  Then, put the drain plug back in, pump 3 litres back in through the fill plug with the fitting and pump, disconnect the fill fitting and replace the fill plug, start the car and run for another 3 minutes (making sure the temp is still under 40oC). The manual then asks for a 3rd "spill and fill" just like above. I also did that and so had put 13l in by now.  This time they want you to keep the engine running and run the transmission through R and D (I hope the wheels are still off the ground!) for a while, and allow the trans temp to get to 40oC, then engine off. Finally, back under the car and undo the fill plug to let the overfill drain out; it will stop running when fluid is at the top of the levelling tube. According to the factory, that is job done! Post that, I reconnected the fill fitting and pumped in an extra 0.5l. AMS says 1.5l overfill is safe, but I started with less to see how it goes, I will add another 1.0 litres later if I'm still not happy with the hot shifts.
×
×
  • Create New...