I've got a problem with my 99 Civic with a Turbo LSVTEC and it will soon become an even bigger problem as the summer rolls in.

I'm monitoring the coolant temp with both a B&M Electronic Water Temp Gauge tapped at the cylinder head, replacing the stock temp sensor (to the gauge cluster) AND at the thermostat through Hondata S300.

Coolant temperature @ 70 mph without heater = 195 - 205
Coolant temperature @ 70 mpg with heater on full blast =190 - 200
Coolant temperature @ 0 to 50 mph without heater = 195 - 215+
Coolant temperature @ 0 to 50 mph with heater on full blast = 190 - 205

Engine specs:

Tuned by Slowmotionmotorsports
Fresh LS VTEC with plenty of forged goodies and the proper headgasket.
Turbo @ 18 psi.
C&R Aluminum Radiator
Brand new thermostat and gasket (180 degrees or so?)
Permacool 12" 1650 CFM radiator fan. Comes on at 180 degrees and 0 to 35 mph.

Everything seems to be functioning very well. No coolant loss, or bubbles in coolant. No oil leaks. Great compression. Everything is fresh. Engine only has 4,000 miles. Nothing wrong, except it seems to be running way too hot, and when the summer rolls in, i really don't want to be running this car (daily driver) with the windows up (raining outside) and the heater on full blast.

Anybody got any suggestions at all?

Also, i've noticed that if I cruise on the highway in 4th gear instead of 5th (which I only did for 20 seconds or so), the engine temps drop substantially... like to 185-190. Leads me to believe that the water pump is not flowing the coolant enough at lower RPMs.

 

It may be your tune. Maybe your leaning out real bad.

 

On the freeway my AEM Wideband reads around 14.2 or a little less. Is that good or bad?

 

sounds like the typical turbo honda. add a fan shroud, get a better fan or both.

turbo blanket, wrapped mani, etc will also help reduce heatsoak

 

Really no room for the shroud. I'll try the header wrap first and then maybe purchase one of those expensive turbo socks.

Thanks.

 

any pics of the bay? a shroud is going to be your best bet.

also, turbo blankets can be had for $125, cheaper than a hg replacement or new engine build

 

I'll upload a picture of the engine bay tonight. Could my water pump be failing or something? Could it be anything else? Would an oil-cooler help?

 

I would assume that during your build you rplc'd the water pump and oil pump. Did you?

I have a heating issue as well. I and running a percision 750 i/c which blocks my radiator and I think it is two main things. The 1/2 radiators and the air flow.

Here is a pic of mine and I am logging up to about 212 via my S300 and 205 via my autometer which is in the stock gauge sensor. I am fine at idle w/ the autometer reading 180 and the S300 reading 195.