[solved] Need help, car heats up on VTEC! But only on very hard runs!

[Lukezen27]

Looks like car is juat getting hot coz its being pushed, and my last option is investing in a low temp thermostat to move the hot coolant out of the block sooner!

But aren't these bad for daily driven cars?

Na low temp thermostats are fine as long as you don’t get one with an extremely low opening point..
Stock B16/18 open at 87-90c from memory, just get a 87c or 82c unit if you’re worried but they go all the way down to 65c I think.
Sounds head gasket related to me and possibly why the previous owner ran without a thermostat

Bubbling out of overflow bottle can point to a leak/break in the head gasket between the blocks water pipes and one of the cylinders... this type of leak can sometimes only show-up after long driving due to heat soak/build-up and not show-up on small runs even if you hit it hard.
This type of leak pushed hot air from the cylinders into the cooling system and does two things.. one, added heat and two, added air the cooling system than needs to be pressurized to work correctly and thus pushed coolant into the overflow bottle

Things I’d do:

1. Get a low temp thermostats (82c)
2. Make sure your radiator fans connected and working correctly (if not working unplug the fans two pin socket from behind the thermostats and bridge two pins with a paperclip, this with trick the fans into running the whole time but it’s only a temp fix.
3. Make sure you don’t have too much coolant in your system, more water the better in fact.. 10-20% coolant the rest plain water!
4. Make sure the radiator cups sealing and it’s the right pressure spring for your setup.
5. Check for leaks in the water hoses.
6. Maybe get a radiator pressure test a flush.
Remember the cooling system is designed to work under pressure and any leak or air bubble will affect its ability to work correctly and cooling efficacy

Just run no thermostat!

Engines are designed and setup to run with-in a certain heat range for optimal performance and longevity, the cooling system needs to be configed to handle all the different variations.
Not running a thermostat means you actually have no control over the heat/cooling system and temps will fluctuate quite a bit, especially as it’s a daily driver and that’s bad.
Track cars can kind’a get away with no thermostat if needed as they’re being run hard the whole time and need to displace big heat, I’ve been told that it’s very hard to tune a car without a thermostat due to the big temp fluctuations I’ve just mentioned..

[bboyzell]

to me if your cars going fine with daily-driving under 5k-rpm then i would be considering changing your radiator, or at least get it pressure tested in the car.

I have a B16a in my CRX and it always ran stupidly cold, after a year of having i finally checked the thermostat and it was stuck open, got my radiator checked and it had a cracked core, possibly due to the faulty thermostat.

Just my 2c

[EG52NV]

to me if your cars going fine with daily-driving under 5k-rpm then i would be considering changing your radiator, or at least get it pressure tested in the car.

I have a B16a in my CRX and it always ran stupidly cold, after a year of having i finally checked the thermostat and it was stuck open, got my radiator checked and it had a cracked core, possibly due to the faulty thermostat.

Just my 2c

Dude.. Dont you read? It's a brand new dual core aluminum radiator from eBay.. Same problem occurred when I had stock EK4 radiator which is why I changed it..

As above poster has stated it's probably leaking HG and only occurs due heat soak...

I'll look into low temp thermostat as a temp fix as I save for HG change

[Bludger]

you know, that might be your problem.

the new radiator..

lol

[Lukezen27]

Dude.. Dont you read? It's a brand new dual core aluminum radiator from eBay.. Same problem occurred when I had stock EK4 radiator which is why I changed it..

As above poster has stated it's probably leaking HG and only occurs due heat soak...

I'll look into low temp thermostat as a temp fix as I save for HG change

Just make sure you get some tests done before you put her in for a HG

I had this problem with my D16Y1 took her to Hannys and they confirmed it was the HG and they changed it and all was good after that

Some idiot reported my above post.. man up and post your opinion!!!!!!!!

[amant02]

I had the same issue, but it was my radiator rusting from the inside, the previous owner ran just water according to my mechanic that what started the rust ~ personally i think it was me not giving a shit about the car for 6 months and letting sit in the sun lol. After i changed the piping + new radiator oem fixed the problem for me. A temp fix for me was constant flushing of my radiator till i was able to get a new one.

Probs not same problem for you, just finished reading the other responses. Meh just wat i exp'd could help.

[EG52NV]

you know, that might be your problem.

the new radiator..

lol

Man of it occurred with the stock ek4 radiator and new radiator, the problem has got to be else where unless I have really bad luck and my brand new radiator is just as blocked as stock one bit hardly doubt it

[Bludger]

Well, I would say BHG is plausible.....

if you rule out the radiator...

[EG52NV]

Well, I would say BHG is plausible.....

if you rule out the radiator...

Yep, car started to heat up during idle when air con was on... dropped it off $550 later cars got a new HG as the other one was not blown but leaking... case closed

[dc2r-0636]

$550 is cheap for a new head gasket ! Thought it would be over 1k

Thanks for updating with conclusion

[jdm18c]

550 lol who did a hg for that much cheap as

[Lukezen27]

Hannys did my HG for 480 D!6 though is B16 might be a bit more