1986 Toyota Pickup Overheating

CURTDCOOK

MEMBER
1986 TOYOTA PICKUP

Engine Cooling problem
1986 Toyota Pickup 4 cyl Two Wheel Drive Manual 200 + miles

HI, My Toyota truck W/ 200,000+ Miles, oil leaks and all, now has a overheating problem?
I fill the radiator and with in 20 miles or so it starts overheating and the radiator fluid disapppears but don't see any major leaks or puddles any where, My question is:
Is it the THERMOSTAT
or/ WATER PUMP,
I'm unsure what I should try first or what my symptoms mean.
The haeter also gets hotter & hotter as it overheats, I have put in two kinds of radiator stop leak, the first time worked for almost a month but I'm thinking its not a leaking problem,

So again with my symptons, (Overheatong and loss of radiator fluid) could it be the THERMOSTAT -OR- WATER PUMP?

NOTE: just saw the donation option Iam unable to donate at this time plus I would like to see what this site is about first, but if all seems legiate, I will have no problems giving a donation.

Thank You CURT

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

Try the thermostat for a start cheap fix-dont work check water pump if it continues and probable causes.

One way to test for a bad water pump is to squeeze the upper radiator hose when the engine is hot and idling. Careful, because teh hose will be HOT! If you do not feel much coolant circulating through the hose when you rev the engine, the pump may be bad. The other cause might be a bad thermostat that is not opening properly (remove and inspect the thermostat), or a clogged radiator
Have it block and pressure tested-do the block first to pinpoint a combustion leaking into the cooling system or a gas analyzer to sniff for hydrocarbons at the radiator fill neck.

Pressure test: do not do a pressure test if there's leakage at the headgasket this might cause coolant into the cylinders and lock it up or bend a connecting rod if cranked thereafter. The headgasket should be repaired before doing the pressure test.

If the block and pressure test passes check the following:, Pressure test the Rad. Cap, Clogged radiator, air lock in the cooling system, Fan clutch, Radiator electrical fan, collaspe hoses, water pump.