Jump to content
SAU Community

Recommended Posts

M35 overheating

In cold weather, it looses no coolant, and is fine (all winter). But after a few 35 degree plus days it looses coolant and overheats. If i top it up and drive in cool weather, it again looses no coolant and is fine. Last summer it got a new thermostat, radiator and radiator cap, and was holding pressure.

Is your M35 ok in 35+ weather?

How do i troubleshoot this, or are M35s a bit iffy under extreme temps?

Link to comment
https://www.sau.com.au/forums/topic/469153-m35-overheating/
Share on other sites

36 minutes ago, MrStabby said:

M35 overheating

In cold weather, it looses no coolant, and is fine (all winter). But after a few 35 degree plus days it looses coolant and overheats. If i top it up and drive in cool weather, it again looses no coolant and is fine. Last summer it got a new thermostat, radiator and radiator cap, and was holding pressure.

Is your M35 ok in 35+ weather?

How do i troubleshoot this, or are M35s a bit iffy under extreme temps?

Did you bleed it right when you did the rad, thermal stat? Did you do it in winter? Were you able to trace to see where the coolant leak from?

Maybe bubbles still trapped in the system?

I dont' have problems on 35+, having said that, car already came with a Scotty cooling mod, i also just did the thicker radiator, nismo stat, new genuine nissan coolant.

Link to comment
https://www.sau.com.au/forums/topic/469153-m35-overheating/#findComment-7812400
Share on other sites

I didnt do the work last summer, because lazy. Yes always bled. Temp gauge apparently working fine, and giving repeatable results, ie moving above normal level correlates with loss of coolant, and vice verca.

I wonder if i can get a nismo cap for it...

EDIT: R32 and M35 caps are the same so ill try the Nismo from the GTR on it

Link to comment
https://www.sau.com.au/forums/topic/469153-m35-overheating/#findComment-7812404
Share on other sites

Just swap it for anything that fits for a few hot days, even something crappy like a micra.  It also could be a leak that is only obvious under pressure (which it doesn't get to on cooler days) which you could check with a pressure tester.

Link to comment
https://www.sau.com.au/forums/topic/469153-m35-overheating/#findComment-7812409
Share on other sites

Interestingly the M35 spout is 1.2mm higher (seal surface to cap surface) than the R32, and since force = distance x spring constant, so any cap will have less sealing pressure on the M35 compared to the R32 (for the radiators i have)

Link to comment
https://www.sau.com.au/forums/topic/469153-m35-overheating/#findComment-7812416
Share on other sites

NM35 with Scotty's cooling mod.

Lost a litre of coolant over the last few really hot days - including 4 hrs driving (half of it in Sydney traffic) in 38-40 deg. temps. With no air conditioner (another story, but I personally lost a couple of litres of coolant on that drive).

The temp. gauge sat rock-steady on half-way the whole time.

No discernible trace of coolant leak.

Topped it up with pre-mix over a week ago. Since then, temps have been in the high 20's low 30's, and it doesn't appear to be losing coolant.

Now, the temp. gauge needle sits about 1/3rd of a mm below half way. Just like it did before the heatwave.

So that missing litre made some kind of difference.

Radiator cap looks and feels in top nick. No idea where that coolant went.

Interested to see if the change of radiator cap solves your problem, Mr Stabby.

Link to comment
https://www.sau.com.au/forums/topic/469153-m35-overheating/#findComment-7812734
Share on other sites

I have exactly the same issues, however I know that the large alloy radiator is leaking from the top tank on the side (not easily visable). It doesn't leave puddles on the ground, yet drains the reservoir on hot days.

The leak, in my case, was caused by a stray current in the car - kills alloy radiators. I found the leak last time I removed the radiator and it was less than a year old when it started leaking.

Link to comment
https://www.sau.com.au/forums/topic/469153-m35-overheating/#findComment-7813446
Share on other sites

  • 2 weeks later...
On 2/22/2017 at 11:33 AM, Darkmeat said:

Interested to see if the change of radiator cap solves your problem, Mr Stabby.

Update for Darkmeat; swapped the caps between the R32 and Stag. No apparent issues with the Nismo cap on the stag, but it hasnt been hot enough for a proper test. The new 0.9 cap from the stag leaked on the R32, so either its defective as Duncan suspected, or Stags need a greater than 0.9 cap. Seems like the standard pressure ratings are 0.9/1.1/1.3 and IIRC the Nismo is 1.3. I'll try a 1.1 on the Stag next and put the Nismo back on the 32.

 

Link to comment
https://www.sau.com.au/forums/topic/469153-m35-overheating/#findComment-7815860
Share on other sites

Ok, had the 0.9 cap on in 27 degrees with air con and it lost coolant. Now trying a Tridon CB18125 from Supercheap. Looks like the 18125 means 18psi/125kpa. There was also a CB16110. So tar the caps i've seen have pressure stamped on as either the bar number or psi/kpa numbers.

So cap options are;

0.9bar / 13psi / 90kpa

1.1bar / 16psi / 110kpa

1.3bar /18psi / 125kpa

Link to comment
https://www.sau.com.au/forums/topic/469153-m35-overheating/#findComment-7816975
Share on other sites

  • 5 years later...

Scotty mn35 Just been reading alot of your comments and treads, seeing if you have any of your cooling mods laying around..... and some pointers on bleeding the cooling system... I've tried a few times no luck care only over heats in hot weather, I've ordered new water pump thermostat and looking at replacing the radiator just for peace of mind but still sounds like from what I read it's air block..... only started happing after I blue the heater bypass hose on the front of the motor..

Link to comment
https://www.sau.com.au/forums/topic/469153-m35-overheating/#findComment-7973991
Share on other sites

My cooling issues were blocked radiator and weak fan clutch, not bleeding issues. I replaced the radiator with a Fenix ($400), which is higher capacity/wider than the stocker (~$800). Here's how to fix the fan clutch;

Re: air block/heater bypass hose, don't know what that is, but if its bled it should be fine. Just follow the bleeding guide.

Link to comment
https://www.sau.com.au/forums/topic/469153-m35-overheating/#findComment-7973994
Share on other sites

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

    • OK, so regardless of whether you did Step 1 - Spill Step 2 - Trans pan removal Step 3 - TCM removal we are on to the clean and refill. First, have a good look at the oil pan. While you might see dirty oil and some carbony build up (I did), what you don't want to see is any metal particles on the magnets, or sparkles in the oil (thankfully not). Give it all a good clean, particularly the magnets, and put the new gasket on if you have one (or, just cross your fingers)
    • One other thing to mention from my car before we reassemble and refill. Per that earlier diagram,   There should be 2x B length (40mm) and 6x C length (54mm). So I had incorrectly removed one extra bolt, which I assume was 40mm, but even so I have 4x B and 5x C.  Either, the factory made an assembly error (very unlikely), or someone had been in there before me. I vote for the latter because the TCM part number doesn't match my build date, I suspect the TCM was changed under warranty. This indeed led to much unbolting, rebolting, checking, measuring and swearing under the car.... In the end I left out 1x B bolt and put in a 54mm M6 bolt I already had to make sure it was all correct
    • A couple of notes about the TCM. Firstly, it is integrated into the valve body. If you need to replace the TCM for any reason you are following the procedure above The seppos say these fail all the time. I haven't seen or heard of one on here or locally, but that doesn't mean it can't happen. Finally, Ecutek are now offering tuning for the 7 speed TCM. It is basically like ECU tuning in that you have to buy a license for the computer, and then known parameters can be reset. This is all very new and at the moment they are focussing on more aggressive gear holding in sports or sports+ mode, 2 gear launches for drag racing etc. It doesn't seem to affect shift speed like you can on some transmissions. Importantly for me, by having controllable shift points you can now raise the shift point as well as the ECU rev limit, together allowing it to rev a little higher when that is useful. In manual mode, my car shifts up automatically regardless of what I do which is good (because I don't have to worry about it) but bad (because I can't choose to rev a little higher when convenient).  TCMs can only be tuned from late 2016 onwards, and mine is apparently not one of those although the car build date was August 2016 (presumably a batch of ADM cars were done together, so this will probably be the situation for most ADM cars). No idea about JDM cars, and I'm looking into importing a later model valve body I can swap in. This is the top of my TCM A couple of numbers but no part number. Amayama can't find my specific car but it does say the following for Asia-RHD (interestingly, all out of stock....): So it looks like programable TCM are probably post September 2018 for "Asia RHD". When I read my part number out from Ecutek it was 31705-75X6D which did not match Amayama for my build date (Aug-2016)
    • OK, Step 3, if you need to remove the valve body, either to replace it, the TCM, or to do a more complete drain.  First, you need to disconnect the TCM input wires, they are about half way up the transmission on the drivers side. One plug and the wires are out of the way, but there is also a spring clip that stops the socket from sliding back into the transmission. On my car the spring clip was easy to get, but the socket was really stuck in the o-ring of the transmission housing and took some.....persuasion. You can see both the plug to remove (first) and the spring clip (second) in this pic Incidentally, right next to the plug, you can see where the casting has allowance for a dispstick/filler which Nissan decided not to provide. there is a cap held on with a 6mm head bolt that you can remove to overfill it (AMS recommend a 1.5l overfill). Final step before the big mess, remove the speed sensor that is clipped to the valve body at the rear of the box.  Then removal of the Valve Body. For this the USDM Q50 workshop manual has a critical diagram: There are a billion bolts visible. Almost all of them do not need to be removed, just the 14 shown on the diagram. Even so, I both removed one extra, and didn't check which length bolt came from which location (more on that later....). Again it is worth undoing the 4 corners first, but leaving them a couple of turns in to hold the unit up....gravity is not your friend here and trans oil will be going everywhere. Once the corners are loose but still in remove all the other 10 bolts, then hold the valve body up with 1 hand while removing the final 4. Then, everything just comes free easily, or like in my case you start swearing because that plug is stuck in the casing. Done, the valve body and TCM are out
    • OK, so if you are either going for the bigger fluid change or are changing the valve body which includes the Transmission Control Module (TCM), first you should have both a new gasket 31397-1XJ0A and a torque wrench that can work down to 8Nm (very low, probably a 1/4 drive one). You can probably get by without either, but I really didn't want to pull it all apart together due to a leak. First, you now need that big oil pan. The transmission pan is 450 long x 350 wide, and it will probably leak on all sides, so get ready for a mess. There are 24x 6mm headed bolts holding the pan on. I undid the 2 rear corners, then screwed those bolts back in a couple of turns to let the pan go low at that end, then removed all the middle bolts on each side. Then, undo the front corner bolts slowly while holding the pan up, and 80% of the fluid will head out the rear. From there, remove the remaining bolts and the pan is off. You can see it is still dripping oil absolutely everywhere...it dripped all night.... I got another couple of litres when I removed the pan, and then another few when I removed the valve body - all up another 4l on top of the 3 already dropped in step 1.
×
×
  • Create New...