Timing/heat issues?

ptothej · Post by **ptothej** » Wed Jan 23, 2008 11:21 am

I recently read a post on a tercel which was having problems advancing itself, but how it would get good power and fuel mileage. That made me start thinking about how I could get more out of the stock engine, and timing has always been one thing that I like fooling with on my vehicles.. so I found some bpr8es NGK's, yes very cold but a start to allow me to advance my timing. Now I have the timing quite advanced and no pinging, but a problem has occured, it seems to me that it is getting hotter and hotter the more you drive it whether that be up hill or on a flat with nothing to bring it under control.. and it has been the coldest temperature that we have experienced all this winter where I live. Now writing this I started to think about possibly a cooling fan thats not coming on.. but if not, could this be related to the timing? Another point I will add, is I dont think it is a coolant issue, because I have the fan on high, and the temperature seems to stay the same.. it doesnt get cold on me like a loss of coolant problem.. the other thing I was thinking is maybe a coolant temp sensor problem. Any ideas?

xirdneh · Post by **xirdneh** » Wed Jan 23, 2008 1:59 pm

[quote="ptothej"] Now writing this I started to think about possibly a cooling fan thats not coming onquote]

when you are cruising down the road the radiator fan should not come on because the air passing thru the radiator should be doing the cooling.
the radiator fan on all the tercels i have messed with only came on at very low speeds or when car is stopped and idling.
i have experienced a rising temperature gage at high constant speeds (65-75 mph) in cold weather (16-25 deg) several times and i have never figured out why.

ptothej · Post by **ptothej** » Wed Jan 23, 2008 4:35 pm

Hahah Im so brain dead sometimes, of course it shouldnt be on when driving.. but it is downtown stop and go.. so perhaps thats not enough flow to keep it cool, which I will go back to checking the damn fan, and if thats on, Im gonna go after the temp sensor, and if not that I will take our shops infa red thermometer and check the temp of the rad hoses and radiator to see if everything is telling me the truth or not.. Adding another point, it did keep cool (under normal temp) when I was coming down from up the hill on a road that kept me at a constant 60-70km/h, and no throttle.. all coasting.

Post by **ARCHINSTL** » Wed Jan 23, 2008 5:37 pm

xirdneh wrote:i have experienced a rising temperature gage at high constant speeds (65-75 mph) in cold weather (16-25 deg) several times and i have never figured out why.

Well - I'm glad someone else reported this...I never noticed this in my '83 back in the day.
I have, however, noticed this occurring this Winter (not the last two, though). It seems that the colder it gets, the higher the needle goes on the gauge (just to what Toy says is "normal" high, though). I thought something was wrong, so checked clamps, hoses, and fan, and all checked out OK.
At "around town" speeds, the needle stays below the mark, as it does all Summer. But at highway speeds it is higher ...why?
Dunno, but all seems OK...
Tom M.

keith · Post by **keith** » Wed Jan 23, 2008 6:19 pm

Try a new radiator cap.

takza · Post by **takza** » Thu Jan 24, 2008 5:27 am

If you have unexplained "hot" it could be the head gasket allowing exhaust into coolant. It also could be your advanced ignition causing a kind of self fueling reaction?

ptothej · Post by **ptothej** » Thu Jan 24, 2008 9:35 am

Perhaps a coincidence, perhaps the reason I had this problem in the first place.. took some timing out in my quest to find its optimum spot, and car seems to be back to normal..

ptothej · Post by **ptothej** » Thu Jan 24, 2008 10:48 am

Bahahahahahahahahah

Car is not back to normal.. normal temperature on the gauge, yet I froze my ass off all the way to work. I was blaming my thermostat, until I realized that the lower rad hose was cooler then the upper.. Im thinking radiator issues.. probably plugged.. ugghhh.

ptothej · Post by **ptothej** » Thu Jan 24, 2008 2:09 pm

So I go for lunch and the car is back to normal.. I check my antifreeze at my dads and find it to be very lacking in the strength department.. so I go back to my original thought which I thought was a stupid idea, that being that when I turned my heater fan on before the car was warm, that I froze my heater core and or lines going in and out of it.. anyways obviously when I did my thermostat I didnt check to see if the owner before me kept the antifreeze strength up, seeing that there was a new water pump on it

shonuffisthemaster · Post by **shonuffisthemaster** » Fri Jan 25, 2008 2:34 am

I've had the same issue, gauge about 2/3 of the way up going 65 in -10 to -15 weather, I have great heat though:)

one easy way to check the rad fan is just pull the temp sensor connector out of the radiator, this will turn the fan on all the time, if you've still got an overheating problem its something else (also a good emergency fix for a non working sensor)

ptothej · Post by **ptothej** » Fri Jan 25, 2008 12:08 pm

Thats a pretty interesting fact.. thanks:)

simon84 · Post by **simon84** » Fri Feb 29, 2008 7:08 pm

Did you figure this out?
I have a similar thing going on with my 87 t4wd 4ac.
First I had no heat, then I changed the thermostat and now it's running kinda warm and I have plenty of heat (So I'm confident that the water pump works). It was up near the red on the highway the other day. So I turned around to go home and then it came back down to just over half on the temp guage so I ended up completing the trip. The fan runs most of the time now. I think it could be a bad t-stat or possibly a plugged rad. The lower rad hose stays cold while the top is hot. I have a new t-stat to replace again and then I may do a rad flush if that doesn't help. I'll also try to make sure the fluid mix is right.
I have already replaced the head gasket and I don't want to cook it again.

keith · Post by **keith** » Sat Mar 01, 2008 6:56 am

Radiator cap.

Post by **Petros** » Mon Mar 03, 2008 6:44 pm

A plugged up rad will run hot, heat up on the up hills, and cool off on the down hills, and it will cool off when you turn the fan up on the heater. that indicates limited cooling capacity.

A bad T-stat that only opens part way will also act like that, best test it even if new (I have had a batch of bad ones lately). And as Keith pointed out, a bad cap can allow you to loose pressure/coolant, if it is questionable just replace it (they are cheap).

You also might inspect that the lower hose is not collapsing or kinking when you speed the engine up. Sometimes a bad hose will "suck closed" when the water pumps sucks on the lower hose, and starves the engine of coolant.

A rad shop, for a fee, can test the radiator for flow if there is a question about its ability to cool. But is sounds like if the lower hose is cool and the upper hot, it is doing its job. Hot coolant goes in the top, cool comes out the bottom. Verify everything else is working properly before you replace the rad, it is the most expensive part of the cooling system.

simon84 · Post by **simon84** » Tue Mar 11, 2008 4:30 pm

I just replaced the thermostat in the 87 (for the second time) and now the heat stays at about 1/4 on the guage. Seems to have done the trick.
Where should the temp guage sit most of the time?

My 84 tercel is sitting at about 1/2. I'm thinking of doing that thermostat too.

Tercel4WD.com

Timing/heat issues?

Timing/heat issues?

Re: Timing/heat issues?

Re: Timing/heat issues?