Ok. Driving the other day and I start to smell coolant. I see a bit of smoke. I pull right over. Temp is fine. I look and see small puffs of smoke off the top of my Mishi rad. I have a hard upper pipe and a JMF coolant overflow. I thought it was the over flow hose I replaced it. NADDA. I checked the lower hose and its not leaking. I look under the car and there are drip marks on the bottom of the rad. This radiator is about 6 months old. Could there be a leak in the core? I have no temp issues I just can't see where its leaking from but its def leaking. Any thoughts?

 

Go to napa or another store and get a coolant pressure tester. Pump system up to operating pressure bout 15 psi look for leaks and listen for escaping pressure

 

[QUOTE=Murf;9710014]Go to napa or another store and get a coolant pressure tester. Pump system up to operating pressure bout 15 psi look for leaks and listen for escaping pressure looks like this

http://www.harborfreight.com/radiato...kit-65053.html

 

Wow thanks. Stupid question but will ask. I assume I drain the coolant first before I test this?

 

nope, do not drain coolant system is pressuried in place also check you radiator cap .

 

Thanks again

 

prob the cap. i had to replace my mishimoto cap with oem one due to same issue.

 

Ill help ya out man theres possible only 3 places it could be leaking right there, either
A) its due to where the drain plug is on bottom back side passenger side of radiator, make sure that plug is tightened to recommended lb/ft.
B) the cap is leaking even with a tight seal on the filler neck. Which case replace it. Mine went bad only part of my mishimoto showing signs of wear in almost 3 years.
C) its either leaking from where a weld is, or the weld around the filler neck to the actual radiator.

A coolant pressure tester will tell you that, now coolant needs to be filled to almost max, once youve identified where its leaking from, make sure you pressure test the cap.

should be straight forward after youve checked that, good luck.

 

Ok ran to pepboys and changed my cap out. Still smoking. Now my coolant level hasn't really changed and it only puffs smoke at idle but a very strong smell of coolant. I contacted mishi so probably going to get a warranty replacement. Issue is I have to keep driving the car. This will be my 2nd replacement mishi radiator. The cap is only 6 months old.

Oh and petcock(spelling) is tight.

 

had this issue and it was also the cap... when the car was hot I could press down on the mishimoto cap and coolant would spray out.

replaced with the OEM cap and all was fine. I do when starting my car after settling for some time get a coolant smell but no leaks and the reservoir stays pretty much level.

If you just replaced the cap give it a couple days and see if it settles first.

 

thanks but the smoke is coming from the middle of the rad. I think the core is bad. Mishi is sending me out a replacement. Replacing the cap didn't help. Still was smoking. I will update the thread when I get the new radiator.