over heating problem...maybe?

[jp02ti]

My temp gauge has been running around 3/4 to 7/8 on the last few drives, which is unusually high for the ti. it seems to usually run around 1/2 to 2/3. lower rad hose was COLD, upper rad hose was hot.

first i thought it was the thermostat, so i pulled my spare, tested it in boiling water (it worked) then installed.

no change.

next, water pump. installed, drove, no change. lower rad hose is still cold, upper rad hose is hot, gauge is running between 3/4 and 7/8.

timing seems ok although i didn't put the light on it. I figure if it is close enough tat it looks ok it can't be messing with the temp that much.

is it possible that a gauge could go "off" that quickly? I drove it one day, long distance from Birmingham home and the next time i went out the temp was all messed up.

If i get it checked with a hand held temp sensor (like at Autozone...) then what temp am I looking for on the valve cover at normal operating temperatures?

thanks,

Jon

[bills2002]

No info on the temps but I am curious what would happen if you unhooked the lower hose and stuck a garden hose in the filler neck. Sounds like a flow problem in the rad.

[c.d.iesel]

blocked radiator core?

your not eliminating the air pocket trapped

in the cooling system every time you drain.open

it to replace something?

leaking head gasket ?

try a NEW thermostat ?

clean the temp gauge/cluster/temp sender wiring connections,

cluster grounding?

running out of guesses here.

[jgerock]

How old is the radiator Jon? I will refrain from my usual comments.

Jim

[jp02ti]

hehe..yes Jim, send the car to you and all my problems will be solved. riiiight...

as for the rad, it must be less than 10 yrs old since I replaced it, and I've been driving the car around for 10 years now.

I did not do the "hook the hose up" and check the throughput of the rad. seems this could be a likely cause though as the lower rad hose was cold.

refresh my memory here - the fluid goes into the bottom and out the top or the other way around?

when the thermostat is open which end does the water go into the rad, upper or lower?

I should also check the temp sender unit and make sure it is clean. I have previously grounded the gauge cluster, but I should check that wring again.

Jon

[OriginalOwner]

fluid flows into the radiator at the top, departs from the bottom up into the thermostat.

an idea: remove the radiator cap, start the engine, and get everything warmed up nice and hot.

When you increase engine rpm, can you see fluid "obviously" flowing into the radiator ?? On mine, it is quite obvious the fluid is flowing into the radiator, there is a nice current from the fluid inlet on the left flowing to the right.

Since the lower hose (radiator outlet) is cold, my first wild guess is a very seriously blocked radiator. But then again, a not-opening thermostat won't let fluid out of the radiator ...... and since the thermostat seems to be OK, you should be getting some minimal flow through the radiator sufficient to heat it all up, especially after a long drive, and thus make the lower hose hot. And since the lower hose is cold, that makes wild guess #2 the thermostat: for some reason it is not opening.

Cheers,

Carl

[tjones02]

Have you been burping the lower hose to be sure the t-stat has water on both sides? I nearly always have to burp the loser radiator hose with M10s.

Once in a while, I also have had to drill a bleed hole in the thermostat plate inside.

Cheers and HTH,

[bills2002]

Have you been burping the lower hose to ,

How does one burp the lower hose, pray tell Tom? Inquiring minds need to know.

[jp02ti]

fluid level is fine, and I do have an electric fan installed.

between the electric fan and the heater on full blast I can keep the temp under the red.

[tjones02]

Have you been burping the lower hose to ,

How does one burp the lower hose, pray tell Tom? Inquiring minds need to know.

One or both of two ways.... repeatedly squeeze the hose til you don't hear water bubbles inside and or loosen the clamp at the bottom of the t-stat till you get water out.

[Guest Anonymous]

first determine if it is a temp sensor issue or a coolant issue. must be full of coolant to immerse the temp sensor in hot fluid otherwise its measuring air. suggestions re filling on inclinded driveway, keeping the heater box valve open, and fill several times, then run engine, then fill, then run engine etc.

Then its on with the temp sensor. must have long enough stem to dip into coolant in splitter body where boss is. make sure its oem or equiv. and that its working properly. make sure its a match ohmically for your temp guage. there is a chart somewhere to identify the ohmic values at diff temps. I understand that there are sensors out there with a different curve that makes the meter run incorrectly. if that doesnt work, get a 'mechanical' sensor and guage from O'Reillys or Autozone ($15) with a metric adapter from EBay (14mm) and test. The electrics on these old cars float like crazy and the needle gets some of that offset electricity. Grounding sometimes helps. Thats about all that anyone can say.

[OriginalOwner]

cooling "problems" always seem to have plagued my 2002tii. Don't know how many of them were operator-error-induced. I have many years of thought trying to figure it out. Here's some ramblings .....

the more I think about your problem, the more I'm thinking it is radiator. I think that because I just experienced another series of cooling "problems" earlier this summer. And I even got 'em resolved.

My problem was 2-fold: 1) clogged radiator; 2) too much antifreeze.

I pulled the radiator and turned it upside down, stuck a garden hose into the outlet hose & used rags to seal it up tight, then turned on the water full blast. I washed out a lot of gummy stuff, probably old Bars Leak and such, which was probably laying on top of the tubes where I couldn't see it. I was amazed. When I refilled it I estimated a mixture of 15%coolant/85%water. I would run all water but coolant has lube and corrosion protection properties so it's good to have some.

The engine has been running nice and cool ever since, always below the 1/2 mark. I use a 70-deg C thermostat, and will experiment with an 80C to see what happens.

Cheers,

Carl

[jgerock]

One NCC'r had a overheating issue with his squarelight car. Some of us tried some basic things like boiling the thermostat and burping the system. The temp. gauge and radiator would be fine idling in the driveway, but not too long after driving the car, it would overheat. Strange: more airflow = higher temperature.

Turns out the radiator was clogged. A good used 320 radiator was installed and the problem was solved.

I still think you have a funky sticking thermostat or clogged radiator Jon. Good time to upgrade to a Silicon Garage 3-row.

BTW - those coolant branches (inlet manifold) can clog up if the coolant hasn't been changed regularly - especially on tii's with the small outlet that feeds the KF warm-up regulator.

[OriginalOwner]

+1

I have a Silicon Garage 3-row.

Mark Preisendorf is the new contact man for the Silicon Garage 3-row radiators: silicongarage02@gmail.com

Cheers,

Carl

[CLIMBERNYC]

borrow an IR temp gun and aim it at the upper radiator to check temps to see if they correspond with gauge. replace temp sensor. burp lower hose with heater open. check ground on gauge. I had similar issue and replaced thermostat, reboiled my modified radiator,etc. In the end, it was the ground.