Ok, so I have been checking everything trying to figure out why my heat won't blow as hot as it should. I think I have foundmy problem. Looks like a slighty blown head gasket(s). I did a compression test and this is what I got:
Cylinder 1 - 180Cylinder 2 - 215Cylinder 3 - 135Cylinder 4 - 110Cylinder 5 - 180Cylinder 6 - 215
Does this sound right to you all? The car does have a slight miss in it at idle, but runs pretty good for the most part.Also, why are cylinders 2 and 6 reading 215? Seems kinda high to me. Anyway I am pretty sure that is why my heat isn't blowingas hot as it should. Does this make any sense??
question regarding head gasket and heater temperature
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NutriaforBreakfast
- Posts: 1316
- Joined: Wed Sep 26, 2007 1:41 pm
- Car: Nissan Maxima 1995 VQDE engine
Re: question regarding head gasket and heater temperature (walterh)
I don't think there is a direct relationship between a blown headgasket and your heater. I think if the head gasket was blown thecar would be overheating and your heater would work very well.
Did you squirt oil in the cylinders to see if the pressure came up?If so, it could also be your rings that are bad. The FSM details howto do a good compression test. You may try the test several timesto be sure you were using the compression test tool correctly.
I didnt see a FSM for the 1993 model so I looked at the data for1994. I was concerned about your compression pressures on yourengine. The FSM listed the PSI for two different engines in the EC sectionof the FSM'
Page 91VG30E EngineStd PSI = 173Min PSI= 128Difference Limit=14 psi
Page 97VE30DE EngineStd PSI = 183Min PSI = 142Difference limit=14 psi
Has the car ever overheated? It is possible there is a "distorted"head on the car. This means the metal head is no longer flat and agasket is not sealing. The head is no good if the head is distortedby the manuf. limit.
Check and see if water and oil are mixed in the crankcase. See if there are engine exhaust bubbles in the radiator (open the cap andsee-wait for thermostat to open but dont get burned). See if spark plugsare fouled. Chiltons manual has a good primer to read fouled plugs andrelate this to engine problems.
I would be concerned about a low compression reading before a highone, especially cylinders 3 and 4. I am not sure what the difference limit means so maybe someone else could help. I always thought thecylinders had to have an even percentage difference between themselvesfor the engine to be ok.
Did you squirt oil in the cylinders to see if the pressure came up?If so, it could also be your rings that are bad. The FSM details howto do a good compression test. You may try the test several timesto be sure you were using the compression test tool correctly.
I didnt see a FSM for the 1993 model so I looked at the data for1994. I was concerned about your compression pressures on yourengine. The FSM listed the PSI for two different engines in the EC sectionof the FSM'
Page 91VG30E EngineStd PSI = 173Min PSI= 128Difference Limit=14 psi
Page 97VE30DE EngineStd PSI = 183Min PSI = 142Difference limit=14 psi
Has the car ever overheated? It is possible there is a "distorted"head on the car. This means the metal head is no longer flat and agasket is not sealing. The head is no good if the head is distortedby the manuf. limit.
Check and see if water and oil are mixed in the crankcase. See if there are engine exhaust bubbles in the radiator (open the cap andsee-wait for thermostat to open but dont get burned). See if spark plugsare fouled. Chiltons manual has a good primer to read fouled plugs andrelate this to engine problems.
I would be concerned about a low compression reading before a highone, especially cylinders 3 and 4. I am not sure what the difference limit means so maybe someone else could help. I always thought thecylinders had to have an even percentage difference between themselvesfor the engine to be ok.
Re: question regarding head gasket and heater temperature (NutriaforBreakfast)
I bought this car a few months ago, so I have no idea if the car has ever overheated or not. The only reason I did a compression test was to find out why my heater only blows warm air. The heater doesn't get as hot as it should. I have changed the t-stat, flushed the heater core, jacked the front end up and purged the air out of the heater core 3 separate times. Both heater hoses get hot. I noticed the last time that I bled the system, when I rev the engine with the cap off, I still get bubbles. So, I decided to do a compression test, because I read that a leaking head gasket could put air into the cooling system. What about the intake gasket? I will do another compression test this weekend. Could there be a problem with my valves? Thanks for your help!!!!
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NutriaforBreakfast
- Posts: 1316
- Joined: Wed Sep 26, 2007 1:41 pm
- Car: Nissan Maxima 1995 VQDE engine
Re: question regarding head gasket and heater temperature (walterh)
Yes I think so with the valves. Its been a while since I did a compression test so be sure to get some good reference books. I wonder wherethe FSM is for 1993?
You might make sure the radiator is holding its pressure. I would startwith a new radiator cap. I hope the heater core does not have toomuch junk clogging it or stopping it up or keeping the engine heat fromtranferring to the heator core fins. Did you flush it with or without pressureon the water?
Not sure what you mean by the intake gasket. If you mean intakemanifold gasket, I dont think it affects the heater directly either. A badone would create a missing problem though.
If you had a head gasket leaking, you might have a lot of white smokefrom the exhaust and it would be running REAL bad. With the low compression readings, you may have just now noticed the impendingproblem
You might make sure the radiator is holding its pressure. I would startwith a new radiator cap. I hope the heater core does not have toomuch junk clogging it or stopping it up or keeping the engine heat fromtranferring to the heator core fins. Did you flush it with or without pressureon the water?
Not sure what you mean by the intake gasket. If you mean intakemanifold gasket, I dont think it affects the heater directly either. A badone would create a missing problem though.
If you had a head gasket leaking, you might have a lot of white smokefrom the exhaust and it would be running REAL bad. With the low compression readings, you may have just now noticed the impendingproblem