: acceptable coolant usage?



H-Dmechanic
08-31-10, 09:21 AM
hello all, i was wondering what the acceptable amount of coolant usage is? before i have used a tank of gas the coolant message will come up, and it is almost a full jug low... but it does not show signs of leaking or burning. no coolant in the oil or anything. a friend who used to work at a cadillac dealership as a tech says it needs "crossover gaskets" would this cause a sufficiant enough of a leak that never leaves any trace on the ground yet usses that much coolant?

roym01
08-31-10, 11:51 AM
No coolant usage is acceptable. If you are loosing coolant and can't see any traces of it leaking, you are burning it. Head gaskets.

Lot's of detailed info in this forum if you have the time to investigate.

jimsbox
08-31-10, 12:31 PM
There are a lot of hose clamps where hoses connect to pipes or nipples, I think around 14 to 16 of them. If the system has ever been opened I would check on a warm engine each of these by dabbing a dry paper towel under each connection. Also, check the cross over gaskets on the drivers side. I have had leaks like this that were enough to notice lost coolant but did not leave noticable spots on the ground. Also, could be bad surge tank cap or head gaskets.

Ranger
08-31-10, 01:20 PM
Radiator side tanks and the surge tank are common leak points. They tend to crack over time. Dried Dex leaves a telltale chalky white residue.

H-Dmechanic
08-31-10, 01:51 PM
ok so i took it out heated it up to about 215. i could not see any obvious signs around crossovers beside what lookd to me like alum corrosion. or is this dry dex? also i noticed i shut the car off, and could hear a slight air noise. i checked the cap and there is air excaping from the cap, and a few suttle drips on the floor. my question is should there be air and coolant vapor excaping the cap under normal operating temps?

jimsbox
08-31-10, 02:36 PM
No, as I understand it the cap maintains the coolant under pressure so the boiling point is raised and if using correct mixture of good coolant should not release anything unless the entire system is overpressured due to engine overheating. It only should release pressure if something is wrong.

STSS
08-31-10, 04:01 PM
Start with a new cap....

Submariner409
08-31-10, 04:23 PM
ok so i took it out heated it up to about 215. i could not see any obvious signs around crossovers beside what lookd to me like alum corrosion. or is this dry dex? also i noticed i shut the car off, and could hear a slight air noise. i checked the cap and there is air excaping from the cap, and a few suttle drips on the floor. my question is should there be air and coolant vapor excaping the cap under normal operating temps?

The proper coolant level in the reservoir is half full, cold. Your pressure cap is either 16 or 18 psi which gives boilover protection to 265 degrees: You hear hissing there at 215 (normal temp) and it's new cap time. (Or properly tighten the one you have - screw on) Entirely possible for your coolant to go to 220 on occasion: normal. Fans go to SLOW at 224 or whenever any A/C function, including defrost, is used.

Hmmmmmm...................1996 Deville - do you have the old style 2 - click coolant reservoir cap with ears ?? Check the rubber seals in the main cap (overflow) and the spring cap (pressure seal) part.

Ranger
08-31-10, 04:41 PM
No, as I understand it the cap maintains the coolant under pressure so the boiling point is raised and if using correct mixture of good coolant should not release anything unless the entire system is overpressured due to engine overheating. It only should release pressure if something is wrong.

OR the system is being pressurized by exhaust gases.

Submariner409
08-31-10, 04:53 PM
ok so i took it out heated it up to about 215. i could not see any obvious signs around crossovers beside what lookd to me like alum corrosion. or is this dry dex? also i noticed i shut the car off, and could hear a slight air noise. i checked the cap and there is air excaping from the cap, and a few suttle drips on the floor. my question is should there be air and coolant vapor excaping the cap under normal operating temps?


In reply to the thread title: Acceptable coolant usage is exactly NONE.

Mark C
08-31-10, 05:40 PM
96's also have a pair of black heater core supply and return pipes that run around the back of the rear head just below the valve cover lip. These things leak like pigs after about 10 or 11 years, especilly if you in a place that uses road salt in the winter.

Ranger
08-31-10, 10:36 PM
I think they all have those lines Mark, but I still have a hard time trying to comprehend how in the hell salt can get up there. :hmm:

H-Dmechanic
09-01-10, 07:58 AM
found it!! a friend and i did a little investigatin last night with a system pressurizer, and found the crossovers were leakin worse then i thought and the little green hose was straight trickling out of a pin hole. the black tubes dont seem to be leaking for now.

Submariner409
09-01-10, 11:38 AM
found it!! a friend and i did a little investigatin last night with a system pressurizer, and found the crossovers were leakin worse then i thought and the little green hose was straight trickling out of a pin hole. the black tubes dont seem to be leaking for now.

Your "green hose" post has a couple of answers............