Koyo Aluminium Racing Radiator - Cap Recommendations

[Osakakev]

Hi,

 

I have the above installed on my DE along with the Koyo high pressure cap but I think this is causing issues.

 

The OEM cap doesn’t fit and Koyo only supply high pressure ones.

 

Tried to google alternatives and sought the help of Torqen without success.

 

Is anyone else running this radiator?

 

Thank you!!

[Adrian@TORQEN]

What are the issues?

[Osakakev]

Not if it is the high pressure cap but it’s running a bit cold (crusing is 70dg)  / coolant doesn’t seem to expand when hot and heating isn’t brilliant.

 

 

[Adrian@TORQEN]

Sounds like air in the system, have you tried bleeding it again? 

[Osakakev]

It’s been fully bled by a specialist so should

not in theory have air in the system 

[Adrian@TORQEN]

Has the thermostat been replaced recently?

[Osakakev]

Yes along with water pump 

[Adrian@TORQEN]

I would try bleeding the coolant again. It's not the easiest job unfortunately, to get it right. Lots of YT videos. 

[miller_350]

.

Edited September 20, 2024 by miller_350
Correction

[Adrian@TORQEN]

The cap is fine. 

[Osakakev]

I’m sure it is but still want to replace it with a standard pressure one if possible.

 

[zeditis]

All the lower pressure cap will do is lower the boiling point of the water and seeing as it's only 70 its not the answer to your problem. The more likely culprit is a faulty thermostat (I've had faulty new ones before now) or as already mentioned possibly air locked the heater usually improves a little with higher revs.

[Osakakev]

Thank you.

 

is 70dg definitely too low for cruising? You can see location of sensor below if this makes a difference 

 

I don’t drive the car hard at all 

[zeditis]

Normal temps are I believe around 90-95 . I'm guessing that's a aftermarket sensor? 

[Ben350]

On 20/09/2024 at 23:18, Osakakev said:

Thank you.

 

is 70dg definitely too low for cruising? You can see location of sensor below if this makes a difference 

 

I don’t drive the car hard at all 

I've had similar issues recently, are you certain of what make/ model of thermostat you run?

 

I replaced a stuck-open OEM thermostat recently with a Mishimoto 68* thermostat. I found my temps were reaching only about 70* when normal driving, a bit less on faster roads and a bit hotter on slower ones with less airflow. When coasting down a hill temps would get as low as 62* so I don't think Mishimoto's claims of it opening at 68* are exactly accurate. I assumed something was wrong with it and to their credit they sent me another after I described my issues. Exact same temps, no change at all.

 

I replaced it again with an OEM-style Motorad thermostat and temps are now bang on with temps sitting in the 80's while cruising.

I'd say your issue may lie with the thermostat.

[Osakakev]

5 hours ago, zeditis said:

Normal temps are I believe around 90-95 . I'm guessing that's a aftermarket sensor? 

 Yeah it’s an aftermarket one, recently installed although previous reading was similar 

[Osakakev]

3 hours ago, Ben350 said:

I've had similar issues recently, are you certain of what make/ model of thermostat you run?

 

I replaced a stuck-open OEM thermostat recently with a Mishimoto 68* thermostat. I found my temps were reaching only about 70* when normal driving, a bit less on faster roads and a bit hotter on slower ones with less airflow. When coasting down a hill temps would get as low as 62* so I don't think Mishimoto's claims of it opening at 68* are exactly accurate. I assumed something was wrong with it and to their credit they sent me another after I described my issues. Exact same temps, no change at all.

 

I replaced it again with an OEM-style Motorad thermostat and temps are now bang on with temps sitting in the 80's while cruising.

I'd say your issue may lie with the thermostat.

Sort, I believe I bought an OEM one but was off eBay and not from the the UK. Maybe it wasn’t the bargain I thought it was…

 

Any easy way to test it? 

[zeditis]

Pan of boiling water and a thermometer 

 

[Ben350]

What he said^ but it's a pain to take it out and have to refill and bleed coolant afterwards. No real easy way unfortunately. 

[Osakakev]

Ah took ages for the garage to get all the air out of the system when changing the radiator so might leave it for a while

 

Cheers

[ZMANALEX]

Definitely a case of air in the system, if the stat checks out okay, but easy to bleed following the correct procedure.

 

I can send your garage a link if that would help them.

 

Looks like you have the temp sender unit installed into the top hose and I assume an aftermarket gauge is fitted in the cab?

 

Might be a plan to hook it back up to the OEM sender unit at the rear of the engine to see what change occurs as the top hose temps are different from the OEM position at the rear of the engine.

 

 

 

[Osakakev]

Thank you, that would be great.

 

Yes aftermarket gauge fitted in the cab, still have the stock one as and that is steady at just under halfway.

 

Would generally the top hose temp be less than the rear?

[ZMANALEX]

So you still have the stock gauge fitted and hooked up to the oem sender at the rear of the engine which is showing the correct temps?

[Osakakev]

Stock gauge is still there and as far as I know still hooked up to the OEM sender. It goes to just below halfway and gets there before aftermarket gauge gets to it’s fully warmed up temp 

[ZMANALEX]

So what gauge do you prefer to believe?

 

Nissan installed the sensor in the rear cross over pipe for a reason.

 

In situations where I have over or under temperature issues, I simply use an infrared temp. thermal gun to identify the cold and hot spots. Great for also keeping check of your tyre temps when on track, so multi use.

 

Available from £25.00 up.