I have a 1980 cabby with a 91 Gti 8 valve motor. Keeps overheating. I think the problem is a combo of low oil and low coolant.. That I can take care of.. but how much coolant goes in it? and do you just add it straight in the radiator cap on the drivers side?

Engine or hydraulic system overheating Coolant system low on coolant in 6020, 6030, 6030 Premium, 7020, 7030 and
7030 Premium Series Tractors.

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Symptoms
After several hours of work, warning system indicates hot engine coolant or hot hydraulic oil.
Situation or Problem
Coolant level in reservoir is between the "MIN" and "MAX" range but engine or hydraulic system is overheating.
Summary
Air is entering cooling system, hindering coolant flow. Check coolant level. Fill to the "MAX" line on the coolant reservoir.
Bleeding Cooling System:
The bleed valve (see Operator's Manual for location) on the radiator must be closed when the tractor is operating. Open the valve when coolant is drained or filled. If the bleed valve is left open, coolant will internally bypass between the low temperature circuit and engine high temperature circuit causing overheating. When bleeding the system, open the bleed valve and run the engine with no load for 5 minutes at 1700 rpm. Then shut engine off for 5 to 10 minutes before closing the drain valve. Check the coolant level. If level is below the "MAX" fill line, repeat this procedure until coolant level stays at the "MAX" line.

ur car is overheating because it does not have the capacity to dissipate high coolant temperature from ur engine to ur radiator or heat exchanger/ check auxilliary fan operation/ if electrically operated check fuse or motor condition/ if no motor check fans silicone oil/ could be too less/ check radiator condition it coul be blocked that why it restrict coolant flow/ check thermostatic valve condition could be stuck up and restrict coolant flow to the radiator...check coolant reservoir if water has oil in it/ if it has oil in it then ur engine cylinder head gasket is broken....

is your oil low if it is add more oil

Hi,
I'm not familiar with your model to know if you have an engine temp guage or a light that would come on if the engine is overheated. You said the motor wasn't overheating under the hood... but you have an overheating problem? Maybe just a tad bit more info...
Are you losing coolant?
The water pump if bad, would probably leak or make terrible racket.
Just to take a shot at it, since you said it blows smoke through the dash... I'm assuming a kindof white smoke with a rather sweet smell? Have you noticed any wetness on the passenger floor at all? If yes to any of this, I would suspect as you mentioned, a leaking heater core. Hope this helps... Good luck!

I want you to take a couple of spark plugs out and examine them. If you find Anti-freeze on them then you may have a blown headgasket. A very common problem of driving a car until it overheats. I really do hope im wrong. Since it is an overhead valve engine with the cam shaft above...its a 1000.00 to 1500.00 dollar job to have it properly repaired. From here out im just going to explain why this happens...
When a car overheats - be it a faulty thermostat...low coolant...or a faulty water pump or improper coolant mixture ratio. The engine gets so hot that it actually makes the top of the engine change shape... it actually changes enough to damage the head gasket. The head gasket keeps the explosion inside the combustion chamber. Keeps the water in its coolant jacket. and keeps the oil inside its ports. When the Headgasket fails. Sometimes coolant gets into the oil (makes a milky residue form on the inside of the oil filler cap...or makes the engine oil look like chocolate milk.) or oil gets into the coolant (makes your coolant have an oil slick on top) It can also cause water to get into the combustion chamber and when the engine is running - blast the combustion back into the coolant (causes the coolant overflow to overflow or spray) or oil gets into the combustion chamber causing the plugs to get fouled (dirty). worse case...all the above happens. I hope this helps in figuring this problem out...i really do hope im wrong about a blown headgasket . As even i tremble in fear of it happening to my car. Good Luck!

replace hoses that feel spongy check coolant level also check oil level low oil can cause overheating too

1st before you drive the car make sure the coolant level is ok,check oil. If the smoke coming out the muffler is white you could have a bad intake gasket or head gasket, check to see if there is coolant in oil, if the oil looks like chocolate milk you have an internal coolant leak. The lights are probably telling you your engine is overheating and low on coolant.

well you didn't specify the year, make, and model of the truck you are asking about so this is the best answer I can come up with. Below is a list I found that says what vehicles are interference motors...

INTERFERENCE ENGINES WITH TIMING BELTS
ACURA
1986-89 1.6L Integra
1991-95 1.7L Integra
1990-95 1.8L Integra
1986-89 2.5L Legend
1992-94 2.5L Vigor
1986-89 2.7L Legend
1990 2.7L Legend
1991-95 3.0L NSX
1991-95 3.2L Legend
AUDI
1970-93 All Except 1970-77
1.9L & 1970-73 1.8L
BMW
1987-95 2.5L 325I 525I
1994-95 4.0L 740I
CHRYSLER
1993-95 1.5L Colt
1987-88 1.5L Colt
1992-95 1.5L Eagle Summit
1987-88 1.6L Colt
1989-92 1.6L Eagle Summit
1994-98 2.0L Neon Stratus
1990-95 2.0L Eagle Talon
DAIHATSU
1988-92 1.0L Charade
1988-92 1.3L Charade
1990-92 1.6L Rocky
FIAT
1974-79 1.3L 128 Series
1979-82 1.5L Stranda
1974-78 1.6L 124 Series
1974-78 1.8L 124 Series
1974-78 1.8L 131 Series, Brava
1979-82 2.0L Brava, Spider
FORD
1981-85 1.6L Escort, EXP
1981-83 1.6L LN7, Lynx
1984-85 2.0L Escort, Tempo
1993-95 2.0L Probe
1986-88 2.0L Ranger
1984-87 2.0L Lynx, Topaz Diesel
1985 2.2L Ranger
1989-92 2.2L Probe
1986-88 2.3L Ranger
1986-87 2.3L Diesel Ranger
1991-98 4.6L Crown Victoria
GM
1986-95 1.0L Geo Metro
1989-91 1.0L Firefly (CANADA)
1985-88 1.5L Sunburst (CANADA)
1985-89 1.5L Spectrum
1990-93 1.6L Prizm, Storm
1981-84 1.8L Diesel (CANADA)
1982-86 1.8L Buick Skyhawk
1990-98 1.9L Saturn
1987-88 2.0L Buick Skyhawk
1988-95 2.3L Quad Four
1985-87 3.0L Buick
1979-95 3.8L Buick
HONDA
1986-87 1.0L Prelude
1973-78 1.2L All
1973-78 1.3L All
1980-84 1.3L All
1973-78 1.5L All
1985-89 1.5L Civic
1988-95 1.5L Civic, CRX
1993-95 1.5L Civic Del Sol
1979-84 1.5L All
1985-87 1.5L CRX
1993-95 1.6L Civic Del Sol
1973-78 1.6L All
1980-82 1.6L All
1988-95 1.6L Civic, CRX
1984-87 1.8L Prelude, Accord
1979-83 1.8L All
1986-91 2.0L Prelude
1990-91 2.1L Prelude
1990-95 2.2L Prelude, Accord
1992-95 2.2L Prelude
1995 2.7L Accord
HYUNDAI
1984-95 1.5L Excel Scoupe
1995-98 1.5L Accent
1992-95 1.6L Elantra
1993-95 1.8L Elantra
1992-95 2.0L Sonata
1989-91 2.4L Sonata
1990-95 3.0L Sonata
INFINITI
1990-92 3.0L M30
ISUZU
1987-89 1.5L I-Mark
1990-93 1.6L Stylus Impulse
1987-89 2.0L Impulse
1981-87 2.2L Diesel Truck
1986-95 2.3L Truck Trooper
1988-95 2.6L Truck Rodeo Amigo
1991-96 3.2L Trooper Rodeo Amigo
KIA
1995 2.0L Sportage
MAZDA
1984-85 2.0L 626
1988-92 2.2L 626 MX6
1989-93 2.2L Pickup
1988-95 3.0L 929 MPV
MITSUBISHI
1985-95 1.5L Mirage Precise
1990-92 1.6L Mirage
1989-95 2.0L Galant Eclipse
1983-86 2.3L Diesel Pickup
1994-95 2.4L Galant
NISSAN
1982 1.5L Centra
1983-88 1.6L Sentra Pulsar
1987-89 1.8L Pulsar
1982-89 2.0L Stanza 300ZX
1984-95 3.0L Maxima 300ZX Pathfinder
PORSCHE
1976-83 2.0L 924
1976-89 2.5L 944 Series
1989 2.7L 944 Series
1989-91 3.0L 944 Series
1976-83 4.5L 928
1984 4.7L 928
1985-91 5.0L 928
1992-95 5.4L 928
SUZUKI
1985-94 1.3L Samurai Sidekick
1989-94 1.3L Swift
TOYOTA
1986-95 1.5L Tercel
1981-83 2.2L Pickup
1984-87 2.4L Pickup
1982-88 2.8L Celica Cressida
1987-94 3.0L 4-Runner
VOLKSWAGEN
1976-91 All Except 1.9 2.1L Engine
1990-92 1.6L Golf (CANADA) Jetta
1990-95 2.0L GTI Jetta GLI Passat
VOLVO
1991 2.3L Coupe 940
1986-94 2.3L 240 740 940

by oil is "watery" I assume you mean to say thin and clean. which is normal however if there is actual water in it meaning is white and milkish looking that could be a big problem the head gasket could be blown or a cooling/oil valley broken. although sounds more like you're just being finicky 104deg. doesn't seem very hot for engine oil to me in fact it should prob. be around 180deg. depending on the oil cooler

I have had same problem .I flushed the motor to clean the water ports inside the motor.It worked for me hope it works for you