Style Posted April 20, 2020 Share Posted April 20, 2020 Just fitted a TT radiator to my NA engined car and threw the NA rad cap back on. The water temp gauge in the dial cluster reads a little past horizontal now and I'm pretty confident that I've got all the air out the system. It sits steady at that temp and heaters blow hot when turned up (not sure if that's relevant). Anyone know if NA's and TT's run at different operating temps or pressures? I've got 1.1 stamped on my rad cap which I'm guessing means 1.1bar. I've seen conflicting information on what the rad caps are rated to with it being either 0.9bar or 1.1bar. Also running a GE water pump. Any ideas? Quote Link to comment Share on other sites More sharing options...
Axl Posted April 20, 2020 Share Posted April 20, 2020 My TT with 1.1 cap runs right in the middle of the temp gauge My 1j with 1.1 cap runs slightly below the middle of the temp gauge but I do have trd vents in the bonnet and holes in the bumper But just a thought how old is your rad cap I did have one fail on me it ain’t much fun fishing springs and bits of metal out the radiator Quote Link to comment Share on other sites More sharing options...
Kearney Posted April 20, 2020 Share Posted April 20, 2020 When i did my TT engine conversion on my 94 N/A i kept the N/A radiator but it kept overheating when you drive it any way at all on boost. I tried everything and couldn't figure it out. I ended up buying a TT Radiator in the end and it solved it. The car was in daily use as an N/A before that with the N/A radiator. Quote Link to comment Share on other sites More sharing options...
Noz Posted April 20, 2020 Share Posted April 20, 2020 What sensor did you use. I run a higher bar on my rad. 1.3 bar. Not that it's related to your issue. Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted April 20, 2020 Share Posted April 20, 2020 I've tried a lot of different combo's of coolant system components (NA/TT Rads, Waterpumps etc). Never seen anything majorly different in terms of coolant temperature under most normal circumstances. Typically when plugged direct to Standalone ECU i see most 2J's floating around the 87-97C range depending on if idling, cruising, flat out etc. If you are regularly going over 100C, then something is not right somewhere. If you can connect to your ECU and track your coolant temperature that way, you will have better data to work with. The stock dash gauge has a silly range of something like 80-105 degrees whilst it's in the middle, so hard to tell if you are okay or on the hotter side of things until its too late. Rad cap pressure rating shouldn't make any difference to your systems ability to maintain a stable coolant temperature. Unless of course your Rad cap itself is on the way out. Are you still using stock viscous fan and shroud? Cheapo aftermarket electric fans with terrible shrouds usually don't help with overheating issues. Make sure when you fill your coolant system that you jack the front of the car up quite high, and keep burping the coolant system until you have no more air. Then start engine and check temps. Is your thermostat operating correctly? Once car is up to temp after a small drive are both the top and bottom rad hoses the same temperature and by feel do they seem to have a similar amount of pressure. Quote Link to comment Share on other sites More sharing options...
Style Posted April 21, 2020 Author Share Posted April 21, 2020 My TT with 1.1 cap runs right in the middle of the temp gauge My 1j with 1.1 cap runs slightly below the middle of the temp gauge but I do have trd vents in the bonnet and holes in the bumper But just a thought how old is your rad cap I did have one fail on me it ain’t much fun fishing springs and bits of metal out the radiator I think the rad cap is as old as the car so maybe a new one would be good. They're only £6 from eurocarparts, so good shout there. Cheers dude! When i did my TT engine conversion on my 94 N/A i kept the N/A radiator but it kept overheating when you drive it any way at all on boost. I tried everything and couldn't figure it out. I ended up buying a TT Radiator in the end and it solved it. The car was in daily use as an N/A before that with the N/A radiator. Almost the opposite of what I'm seeing lol, thanks for the info mate. I has ran fine as an NA-T with an NA rad for years, the engine has been rebuilt now but can't see that contributing to anything. Something's not right What sensor did you use. I run a higher bar on my rad. 1.3 bar. Not that it's related to your issue. Just the stock sensor to the stock cluster mate, I'd heard the stock gauge has a massive range like Mike says below and it's still creeping above that but holding steady at that level. Maybe does have a small air pocket in it somewhere. I've tried a lot of different combo's of coolant system components (NA/TT Rads, Waterpumps etc). Never seen anything majorly different in terms of coolant temperature under most normal circumstances. Typically when plugged direct to Standalone ECU i see most 2J's floating around the 87-97C range depending on if idling, cruising, flat out etc. If you are regularly going over 100C, then something is not right somewhere. If you can connect to your ECU and track your coolant temperature that way, you will have better data to work with. The stock dash gauge has a silly range of something like 80-105 degrees whilst it's in the middle, so hard to tell if you are okay or on the hotter side of things until its too late. Rad cap pressure rating shouldn't make any difference to your systems ability to maintain a stable coolant temperature. Unless of course your Rad cap itself is on the way out. Are you still using stock viscous fan and shroud? Cheapo aftermarket electric fans with terrible shrouds usually don't help with overheating issues. Make sure when you fill your coolant system that you jack the front of the car up quite high, and keep burping the coolant system until you have no more air. Then start engine and check temps. Is your thermostat operating correctly? Once car is up to temp after a small drive are both the top and bottom rad hoses the same temperature and by feel do they seem to have a similar amount of pressure. I'm not sure if the ECU has been hooked up to coolant temp, I think it's just the stock cluster. Unless the stock ECU and loom reads coolant temp? I can try and check the next time I'm out at the car. Rad cap seems to be fine from what I can see, but will order a new one anyway as they're cheap as chips. I'm still on the stock fans and shroud too. I didn't want to lose the efficiency of the stock fan as I don't think it can be beaten without spending £££. I topped up the coolant with one of those funnels that screws into the rad cap and provides a head of coolant. Squeezed the upper hose a few times and burped out some air. Ran the car up to temp until the coolant started to bubble slightly. Upper and lower hoses were both hot and the temp gauge was a line or 2 past horizontal. Even without any driving. It seems to hold there though as I first noticed it when heading to the shops on the motorway. Water pump is brand new as well (NA) so I'd hope the thermostat is working fine. Thanks for the suggestions so far chaps Quote Link to comment Share on other sites More sharing options...
Kearney Posted April 21, 2020 Share Posted April 21, 2020 Almost the opposite of what I'm seeing lol, thanks for the info mate. I has ran fine as an NA-T with an NA rad for years, the engine has been rebuilt now but can't see that contributing to anything. Something's not right Sorry ment to say, is yours an Auto or Manual? Its the manual N/A's that have the skinny radiator. Quote Link to comment Share on other sites More sharing options...
Style Posted April 21, 2020 Author Share Posted April 21, 2020 Sorry ment to say, is yours an Auto or Manual? Its the manual N/A's that have the skinny radiator. Yeah I'm manual mate, the TT rad was about twice as thick! Quote Link to comment Share on other sites More sharing options...
Noz Posted April 21, 2020 Share Posted April 21, 2020 I'd get a new cap. Just to at least remove it from the equation. Quote Link to comment Share on other sites More sharing options...
Style Posted April 21, 2020 Author Share Posted April 21, 2020 Ordered one just there so should get delivered in a few days Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.