Whats the problem?

When I start my car from a cold start - mostly in the AM, the car hesitates to start - but always starts. But the check engine light comes on along with the Vehicle Stability Assist indicator light and the VSA Activation Indicator lights come on. If I let the car warm up and then shut it off and restart, all lights go off except the check engine light. After two or three stops and starts (shut off and restart) the check engine light goes off. I took it too the dealer and they said the computer indicated the cooling system had a malfunction. They did a pressure test on the system which indicated a leak. However, they could not find any coolant leaking from the radiator or belts. They only conclusion they could come to is that the head gasket “might” be cracked. The oil has not indication that the coolant is leaking into the oil. There is no smoke coming from the tail pipes. So they said they think the exhaust is leaking into the radiator and forcing the coolant into the coolant reservoir thus leading to the engine to “overheat”. BUT the engine is not overheating. So I have two questions. 1) what is really happening? 2) if it is a cracked head gasket, will additives to the radiator such as Steelseal or blue devil really work?

I would like a little more information, please

Model year

Assuming the coolant level is steady, hardly ever needs replenishing. And there are no visible signs of coolant leaking anywhere in the engine compartment. Mechanics have chemical tests to determine whether the exhaust gasses are leaking into the coolant. Maybe ask if it makes sense to have one of those tests done.

The car is a 2003 Acura TLS V6 engine

If you have a bad head gasket, the coolant level in your RADIATOR will slowly go down (depending on how bad the leak is) and it won’t return to the overflow tank…Finally the radiator gets low enough to cause over-heating…If you find your radiator full to the brim, chances are your head gaskets are okay…

I’m trying but can’t for the life of me figure out what code would indicate a cooling issue. More likely an ignition or fuel issue.

On my car I get a warning light if it runs too cool, It was just a hair below normal but enough to set off the code. In my case a new thermostat was in order.


P0125 or P0128 . . . coolant temperature failed to rise an appropriate amount in a specified time frame

In other words, you might need a thermostat, because it’s stuck open, or sluggish

These codes can also set when the coolant level is slightly low. If the coolant level is low enough so that the ECT sensor isn’t immersed in coolant, the code can set. I’ve seen it numerous times.

Ok, I,ll defer to the experts. But, if it failed to get to operating temp, why would the cel come on right away instead of after ruNning for a while? Also said light went off after a while… Don’t think I’d let mess with it except for a thermostat and check for leaks. As usual could be wrong but I’d want to see the manual myself before doing a head gasket.

The cel comes on right away because the system takes into account a number of consecutive failures.


A car with a stuck open thermostat will EVENTUALLY reach proper operating temperature

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.

Actually, it sounds like you may have multiple problems. Can you post the codes when you get them read?