after driving, coolant in overflow radiator tank is boiling. Normal?

 

No.

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89 Camaro IROC
350" GM Crate Motor

650 Holley Double Pumper Carb, Crane Energizer Camshaft (278/290 .476/.494), Edelbrock Torker II Intake Manifold, Hedman Headers, Dynomax Catback Exhaust, B&M Holeshot 3000 Lockup Converter(Yeah, its a little big), B&M Stage 2 Shift Kit and plenty more little stuff that has cost me BILLIONS i'm sure.

Stereo: Sony POS Head unit, Sony Explode Amplifier 200x2 RMS, Pioneer 10" subs, Boston Aqustic 6x9 & 4x6's.

MOD's to come: Vortech heads, 1.6 Stamped Rockers, New Head Unit, and some better 10" subs.

 

J/k... Either the ratio of coolant to water is mismatched Or You've just been inducted to the I've Blown My Head Gasket Club. Welcome, It sucks.

Get a coolant ratio tester. 50% coolant 50% water is optimal.

Matt

[This message has been edited by 89 CamaroIROCZ (edited October 22, 2001).]

 

You are overheating. What does the coolant temperature guage say when this happens? There can be multiple reasons for overheating.... cooling fan(s) INOP, thermostat stuck closed, blown head gasket, cracked head or block, running the engine waaayyyyy too lean, etc. etc. .......

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1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

 

Water boils at 212 degrees fahrenheit, and adding coolant raises the boiling point. That means that your engine is running way too hot.

[This message has been edited by rezinn (edited October 22, 2001).]

 

temp gauge is normal, what should i do?

 

Replace the radiator cap (after it cools down).

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"So many Mustangs, so little time..."
ICON Motorsports

 

All those scary stories and nobody thought about the radiator cap until now.

If there's not enough pressure in the system the coolant will boil at a lower temperature. Liquids expand as they heat up, which is why the overflow tank is there in the first place, to catch the expanding coolant. (yes, it does have other purposes as well)

Anyways, the easiest thing to do would be to replace the radiator cap, they're only a few bucks anyways.

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89 iroc-z 305 tbi
k&n filtercharger, open element air filter. nuffin' else

 

i was just doing some routine check up and noticed engine oil was extremely low, added 2 quarts, it it possibe this had something to do with coolant boiling? radiator cap looks fairly new, will probably replace anyway. also, i was looking around the radiator and noticed at the bottom left corner there is a small valve which i believe is supposed to have a tube connecting to it which detects if radiator is low, but tube is missing completely. why would this be taken off, to try to fool the car? sounds odd

 

I wouldn't say nobody thought of the radiator cap..... there simply wasn't enough info to say what it could be.... thus my etc. etc.

It is doubtful that the low oil level is directly responsible for the engine overheating but if the engine has been starved for oil for a long enough time and the internal componants have been worn excessively, (ie bearings are toast) the excessive friction can create a lot of heat which will overheat the engine. That is usually closely followed by a catostrophic engine failure - So like I said, unless you are having lots of other problems like knocking, smoking, or loss of power, the low oil level is very unlikely to be related to the overheating condition.....

I would replace the radiator cap even if it looks new. You often cannot tell what kind of condition the cap is in just by looking at it... And while you are at it, replace the thermostat and flush the cooling system. Thermostats can often get stuck closed and not allow coolant flow when the engine gets hot. All of these componants are maintenance items and NEED to be replaced (or changed in the case of the coolant) on regular intervals anyway.....

The valve you are describing sounds like the radiator drain. Usually that valve is on the passenger side which is generally referred to as the right side (the left and right sides are as you are sitting in the car) but your car could have an aftermarket radiator of some kind that is constructed differently.....

A 1988 GTA won't have a sensor on the radiator or anywhere else to tell what the coolant level is at. They did not have that option on GTAs in that year (not sure when they started that option or if they even did on a third gen....). The only way to tell what level your coolant is at is to check the radiator itself (don't take the cap off when it is hot!!) and make sure it is full and the overflow reservoir is filled to the proper level (it has two lines on it for when the engine is hot and cold).

If you can get access to a cooling system pressure tester kit (rentable from auto parts stores if you don't have one), you can try running the engine with a pressure gauge on the cooling system and see if an excessive amount of pressure (greater than 15 pounds or so) is being pumped into the cooling system which would indicate a leaking compression issue (head gasket, cracked head r block, etc.).

Some ideas for ya..........
Good Luck

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1987 GTA L98 MD8
355, TFS Heads, LT4 Hot Cam
My GTA

The Minnesota F-body Club

 

thanks for the help everyone