Engine: JDM B16a done aprox 110,000kms

Problem: It's summer here in New Zealand and sometimes in heavy traffic the temp needle goes to around 3/4 full. Usually it sits at under 1/2 way. I initially thought it was my fan switch but it appears that my fan works perfectly but the car still overheats.

Now from what i have read there could be a few possibilities:
1. Air pockets in cooling system?
2. Thermostat stuck closed?
3. Water pump?
4. Corrosion in radiator?

How do i test these things and are there any other problems that can cause my car to overheat? Remember it only overheats when the car is stationary or moving very slowly in traffic.

And i have another problem... which i dont know if it is related to this above problem. After I sit at the traffic lights for a while, when i take off the car feels EXTREMELY sluggish. Like there is no power at all, you really have to put your foot down and the car barely moves. The revs seem to take forever to go up and it seems like the revs go up but the car doesnt really move much. This is very noticeable and only happens when the car has been sitting stationary for a little while. Feels like the timing is severely retarted. What could cause this???

Any help appreciated

 

How is it while driving (not stuck in traffic)? If it stays good when driving 60kph, especially accelerating or climbing hills, then I'd say the 4 possibilities you list are OK. Although it never hurts to check for air pockets.

I'd guess your fan switch is turning on at a little higher temperature than it's supposed to? It should be a little higher than your thermostat, so it's not ALWAYS running. But it shouldn't be too high...

 

It does not overheat while driving. Only if its been sitting there for a while. The fan comes on just below half way. Today i took the radiator cap off and turned the car on and waited for it to run to operating temperature. I noticed there was some small bubbles coming out, but not hardout. Please tell me this isnt a blown headgasket !!! There isnt any white smoke at idle though. Or is it normal for some small bubbles to appear? When i rev it some water gushes out. The top radiator hose is hot while the bottom one is relatively cooler.

Well havent driven the car enough since so i dont know if bleeding the air worked. But im concerned that after being stuck in traffic the car has absolutely no power at all, like it just doesnt want to move. Only happens if its been sitting in traffic for a while. I doubt its heatsoak on the intake pipe because its quite well insulated.

Help cheers

 

i would perform a cooling system service.....Drain your coolant.....Go buy a adapter that will fit a funnel to your radiator (they come in a kit), pour coolant into funnel and let the car run intil all the air bubbles are gone(make sure the funnel always has coolant in it).........We recommend this service every 30K miles at the dealer...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tianporn &raquo;</TD></TR><TR><TD CLASS="quote">The fan comes on just below half way.</TD></TR></TABLE>That sounds about right.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tianporn &raquo;</TD></TR><TR><TD CLASS="quote">I noticed there was some small bubbles coming out, but not hardout. Please tell me this isnt a blown headgasket !!! There isnt any white smoke at idle though.</TD></TR></TABLE>You could do a leakdown test. Or I think there's places that can analyze your coolant for traces of exhaust gases.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tianporn &raquo;</TD></TR><TR><TD CLASS="quote">Or is it normal for some small bubbles to appear? When i rev it some water gushes out. The top radiator hose is hot while the bottom one is relatively cooler.</TD></TR></TABLE>When I rev my engine you see it flowing faster. Maybe the churning flow looks like there's a few bubbles? Otherwise that sounds normal.

As far as bleeding all the air out, let it get cold. Squeeze each radiator hose. You should be able to feel the difference whether there's air in there or not, & you'll hear it sloshing around. You should only hear that little rattle-pin in the thermostat.

Dumb idea #1 - Are your fans wired up to both come on with the fan switch? That depends on the year of your car, but maybe you can rig 'em up that way?

Dumb idea #2 - Is the fan wired up backwards? Does it blow air towards the engine like it should? I've heard of them running backwards, so if you're moving maybe 10kph the air pretty much stalls itself.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JimBlake &raquo;</TD></TR><TR><TD CLASS="quote">Dumb idea #2 - Is the fan wired up backwards? Does it blow air towards the engine like it should? I've heard of them running backwards, so if you're moving maybe 10kph the air pretty much stalls itself.
</TD></TR></TABLE>

Is the fan meant to blow towards the front of the car or suck?

Thanks for the suggestions so far, i will see what i can do.

 

It's supposed to suck air thru the radiator, towards the engine. The same direction as air flow when you're driving down the road. If it's wired backwards, it's fighting against the air that comes thru from the car's motion.

 

OK took the radiator cap off and turned the car on to do more testing. This was done after the car had been resting the whole night. There were signs of some small airbubbles sorta like "a goldfish breathing" once in a while so i doubt its the headgasket.

But what i noticed was initially when the car started warming up the top hose was hot and bottom hose was relatively cool/warm. But after idling for around 15-20 minutes the bottom hose was almost if not as hot as the top hose. Whats this problem? Thermostat ******* up?

Cheers

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tianporn &raquo;</TD></TR><TR><TD CLASS="quote">... But after idling for around 15-20 minutes the bottom hose was almost if not as hot as the top hose.</TD></TR></TABLE>So when the thermostat opens up, coolant flows thru the radiator. But it isn't getting cold since there's not a lot of air blowing thru the radiator. Normal so far, I guess.

Try the same thing but jumper the wire for your fan switch, to force the fan to run. Hope this time the lower hose gets cooler. It might be crud coating the inside of the radiator? New radiator or flush with some cleaning stuff.

Still, do a compression test or leakdown test to rule out a headgasket. I kinda think that's not it, but ???