slant 6 heating up after 5 mins idling

-
DartNByYou

DartNByYou

Bit by the Dart
Joined
Nov 16, 2010
Messages
52
Reaction score
0
Location
orange county
hello,

I have a 69 dart with a slant six. It is a recent purchase that i have been working on. Yesterday I started it up and while looking at my gauge it the needle went all the way to the right after only 3-5 mins of idling!!! This is the first time it has done that. It has been at a good temp previously before letting it sit for a month. I do not know what is wrong so i would like some help diagnosing the problem.

I tried putting a new stat in but did not help. what should i do next. I dont wanna have to keep buying parts to chase it if possible.

Thanks,
Dave
 
A few things you can check without having to spend a dime. First, did you do any work to the car or change anything before this problem started? If not I would start by seeing if the gauge is reading correctly. All I do is get an old meat thermometer and put it in the coolant running the engine to see what it says. While you have the rad. cap off you can also look into the radiator and feel the upper hose to see if the water pump is puming coolant. If that checks out then when the engine warms up a bit feel the radiator fins/tubes for any spots that may be a lot cooler than the rest. Sign of a blocked up radiator. Last but not least is since you say it does it at idle it could be the idle screw or passage is gummed up. Just turn the screw in and count how many turns to lightly seat it. Then back the screw completely out and spray inside with carb cleaner and blow it out carefully with compressed air. Replace the screw and reset it to your idle mix setting. Also if you have a fan clutch check and see if it spins alot after you shut the car off and is super easy to spin by hand. these are the main causes I could think of.
 
well it sounds like no fluid flow or a block...

so first i would take the rad cap off (cold) and start it up...

let it idle, watch the gauge and feel the upper hose....

a little under half way the t stat should open...

so watch for fluid flow in the radiator and if it starts to heat up, over half, and there is no flow, i would test the t stat out of the car...
 
honestly, they're a little bit costly but you should invest in a radiator cap that tells you the temperature of the water within....if that tells you it's at normal operating temperature, then you know it's a gauge issue it will save you grief in the long run...
 
Hi all,

I went to the car today and checked some of the stuff mentioned (all but the idle screw, forgot).

I did the meat therm thing and found out the 2 i had were giving me mixed numbers so they didnt help. Eventually, I will get the cap dusterdan talked about but i don't want to buy one now and not have it fit an alum rad when i get one.

looked at the coolant flow from the filler tube and couldnot se an obvious flow. what kind of flow should i be seeing?

Upper hose had no pressure with cap of. had pressure with cap on.(makes sense!).

temp gauge didn't get as hot today but still above normal at 3/4 - 5/6 way right.

Will try screw when i can next weekend hopefully. thank you for the help so far and i will keep everyone posted with an update.

Also, i saw something in one of the threads about drilling an 8th inch hole in the stat to help avoid air pockets..... is this advisable???


Thanks
 
DartNByYou said:
Hi all,

I went to the car today and checked some of the stuff mentioned (all but the idle screw, forgot).

I did the meat therm thing and found out the 2 i had were giving me mixed numbers so they didnt help. Eventually, I will get the cap dusterdan talked about but i don't want to buy one now and not have it fit an alum rad when i get one.

looked at the coolant flow from the filler tube and couldnot se an obvious flow. what kind of flow should i be seeing?
Upper hose had no pressure with cap of. had pressure with cap on.(makes sense!).

temp gauge didn't get as hot today but still above normal at 3/4 - 5/6 way right.

Will try screw when i can next weekend hopefully. thank you for the help so far and i will keep everyone posted with an update.

Also, i saw something in one of the threads about drilling an 8th inch hole in the stat to help avoid air pockets..... is this advisable???


Thanks
Click to expand...

its obvious when the collant is moving...

and yes... i always drill an 1/8 hole at the top of the t stat...

dont waste your money for one of those caps... if you have no flow either the rad is plugged, t stat isn't opening, or the impeller fell/rusted off the pump...
 
well looks like i am pulling the water pump this weekend.

Damn Rust!!! and bad previous maintenance.
 
You must log in or register to reply here.
-

Back
Top