SOURCE: No Heat and Overheating in 1999 Chevy Silverado
hi on thoes trucks the theermostat must be put in with the little hole in the thermostat pointing at 12 oclock or pointing away from radiator to let all air out.and check for a colapsing hose stpoing the coolant from circulating. tyr that first
SOURCE: no heat, replaced thermostat,water pump,heater core, all hose ok
When you put your hand on the inlet & outlet heater hoses are they both hot to the touch ? I mean 'ouch' hot, not just warm.
You might have an 'air lock' in the system if they are only warm, or temp feels quite different between them.
If possible, leave the return heater hose loose, start engine, let it warm up then bleed the system using return hose for a minute or so.
KEEP rad full while bleeding.
tighten hose, then watch the radiator fill hole for signs of air bubbles or frothing coming up thru antifreeze.
If either are present, you may have compression leak !
Another check for compression leak, is put rad cap on, drive around the block twice, let vehicle cool down then slowly remove rad cap & smell at filler hole as cap comes off.
compression leak will smell strong & burn eyes.. & we both know there is only one cure for that situation !!
SOURCE: 2001 Chevy Malibu, 89,000 miles, 3.1 engine, won't start
CLICK HERE for the injector schematic.
CLICK HERE for the Ignition schematic.
Since the PCM uses info gatheres from the crank and cam sensors to calculate ignition - and there are no OBD codes - in all likelihood, the PCM itself is bad.
The Ignition Module, also transmits to the PCM.
It appears after all your testing - that the PCM is at fault.
It does not error report on itself (unfortunately).
The ignition timing is controlled by the Powertrain Control Module (PCM). No adjustment is necessary (distributorless ignition) or possible.
Please see the following....
The ignition timing is controlled by the Powertrain Control Module (PCM). No adjustment is necessary or possible.
The engines covered by this manual are equipped with distributorless ignitions, ignition timing is controlled by the Powertrain Control Module (PCM), as applicable. No adjustments are possible. If ignition timing is not within specification, there is a fault in the engine control system. Diagnose and repair the problem as necessary.
Ignition timing is the measurement, in degrees of crankshaft rotation, of the point at which the spark plugs fire in each of the cylinders. It is measured in degrees before or after Top Dead Center (TDC) of the compression stroke.
Ideally, the air/fuel mixture in the cylinder will be ignited by the spark plug just as the piston passes TDC of the compression stroke. If this happens, the piston will be at the beginning of the power stroke just as the compressed and ignited air/fuel mixture forces the piston down and turns the crankshaft. Because it takes a fraction of a second for the spark plug to ignite the mixture in the cylinder, the spark plug must fire a little before the piston reaches TDC. Otherwise, the mixture will not be completely ignited as the piston passes TDC and the full power of the explosion will not be used by the engine.
The timing measurement is given in degrees of crankshaft rotation before the piston reaches TDC (BTDC). If the setting for the ignition timing is 10 BTDC, each spark plug must fire 10 degrees before each piston reaches TDC. This only holds true, however, when the engine is at idle speed. The combustion process must be complete by 23° ATDC to maintain proper engine performance, fuel mileage, and low emissions.
As the engine speed increases, the pistons go faster. The spark plugs have to ignite the fuel even sooner if it is to be completely ignited when the piston reaches TDC. Spark timing changes are accomplished electronically by the engine and ignition control computers.
If the ignition is set too far advanced (BTDC), the ignition and expansion of the fuel in the cylinder will occur too soon and tend to force the piston down while it is still traveling up. This causes pre ignition or -knocking and pinging-. If the ignition spark is set too far retarded, or after TDC (ATDC), the piston will have already started on its way down when the fuel is ignited. The piston will be forced down for only a portion of its travel, resulting in poor engine performance and lack of power.
Timing marks or scales can be found on the rim of the crankshaft pulley and the timing cover. The marks on the pulley correspond to the position of the piston in the No. 1 cylinder. A stroboscopic (dynamic) timing light is hooked onto the No. 1 cylinder spark plug wire (2.2L engine only, on the 2.4L engines, special adapters are needed) . Every time the spark plug fires, the timing light flashes. By aiming the light at the timing marks while the engine is running, the exact position of the piston within the cylinder can be easily read (the flash of light makes the mark on the pulley appear to be standing still). Proper timing is indicated when the mark and scale are in specified alignment.
WARNING
When checking timing with the engine running, take care not to get the timing light wires tangled in the fan blades and/or drive belts.
The engines covered by this manual are equipped with distributorless ignitions, ignition timing is controlled by the Powertrain Control Module (PCM), as applicable. No adjustments are possible. If ignition timing is not within specification, there is a fault in the engine control system. Diagnose and repair the problem as necessary.
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SOURCE: i changed the water pump thermostat and heater
1)Air trapped in system
2)plugged radiator
3)collapsed heater hoses while engine is running
4) heater control valve
5) blend door motor for hot/cold (VERY COMMON)
Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/sean_54c3a3dc48a7773c
SOURCE: 94 Chevy Suburban runs 1 minute and shuts off like
This is an electronic engine control problem do u have any system fault codes? u need to check them, here is how to do that, go to the link.
http://check-engine-light-codes.blogspot.com/2006/03/gm-1983-95-vehicles-obd1-codes-self.html
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