I've been experiencing over heat problems with my 2003 honda crv. the temperature usually raises when i'm driving in an inclined or hills like roads. i have already over-hauled my radiator, i also had my...
Replacing a cylinder head gasket is a miss or a hit. In some cases, just replacing the gasket may work. But if the cylinder head is bend, dealer may ask to replace it, because "machined aluminum heads rarely works". In this case the cost may be more than $1000. It is a good idea to send the cylinder head for inspection, in a machine shop. They charge $150 for inspecting, checking, cleaning and if necessary machining the head.
If the timing belt will be replaced this is an extra cost. If someone will just replace the gasket, on a bend cylinder head, it is more likely to blow out again. This problem can be solved if the gasket be replaced properly, checking and taking care for the cylinder head too.
As the coolant warms up, it expands and for that reason you have two marks at coolant bottle. Down cold and up hot. It is normal for the coolant to overflow from coolant bottle, if it is filled to the upper mark with engine cold, way up the cold coolant mark. Let engine to cool down overnight and set the level at coolant bottle at the lover mark cold. If it will overflow again this is a bad sign. The pressure at combustion chamber varies from 75 in idle up to 150 or more in higher RPM. If the cylinder head gasket is blown, then gases are blown into the cooling system, increasing the pressure, the radiator cap pressure relief valve is open and coolant is discharged in the coolant bottle. In such cases it is common for the coolant bottle to boil. You can observe gases discharging in the bottle, mixed with coolant, from the cooling system. These are symptoms of a blown cylinder head gasket. Because you replaced it once, there might be a bad (bend, deformed) CYLINDER HEAD too.
To find it out you have to perform cylinder compression test on your car (PROFESSIONALLY).
1. Start with a normal ("static") compression test. To eliminate rings, valves, holes in pistons, that sort of things. A normal cylinder balance test is also helpful (so you know which, if any, cylinder is presenting a problem). Engine should be warm.
2. Put all spark plugs but one back in. Ground that plug wire to prevent module damage. Disconnect that injector on a port fuel system.
3. Put your compression tester into the empty hole. The test can be done without a Shrader valve, but most people recommended leaving the valve in the gauge and "burping" the gauge every 5-6 "puffs".
4. Start the engine and take a reading. Write it down
5. Now goose the throttle for a "snap acceleration" reading. Reading should rise. Write it down NOTE: Don't use the gas pedal for this snap acceleration. The idea is to manually open then close throttle as fast as possible while without speeding up the engine. This forces the engine to take a "gulp" of air.
6. Now write down your readings for at least the bad cylinder (if there is a single bad cylinder) and maybe 2-3 good ones. Make a chart like this: CYL STATIC COMPR IDLE -RUNNING COMPR - SNAP Cyl 1 150 75 125 Cyl 2 175 80 130 Cyl 3 160 75 120 Cyl 4 160 80 125
7. ANALYSIS: Running compression at idle should be 50-75 psi (about half cranking compression). Snap throttle compression should be about 80% of cranking compression.
Consult a professional with the readings. If the gasket is to bad, you may have very low compression at lease in one cylinder.
If you will get a positive confirmation for a bad cylinder head then you have two options:
REBUILD THE CYLINDER HEAD or REPLACE IT.
Nov 10, 2010 |
2003 Honda CR-V