How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Davo Your Own Question
Davo
Davo, Master technician
Category: Chevy
Satisfied Customers: 3253
Experience:  ASE Master Technician also L1 Advanced Engine Performance Specialist
112340
Type Your Chevy Question Here...
Davo is online now
A new question is answered every 9 seconds

Replaced head gasket on 1998 chevy malibu 2.4 when I ...

Resolved Question:

Replaced head gasket on 1998 chevy malibu 2.4 when I started the engine it ran fine except for a rough idle but when i accelrate about 75 rpms it runs very smooth when i turn the a/c on when idleing the engine dies. I have checked for vacuum leaks and didnt find any at all. I also checked for leaking injectors and found none leaking. I replaced the o2 sensor but it still idled the same rough and very low idle. I did get a code on a scan telling me that one or more cyl. missfire. ant ideas ?
Submitted: 10 years ago.
Category: Chevy
Expert:  Davo replied 10 years ago.
You have the symptoms of the cams being out of time.If you didn't use the tools to locate the cam pulleys I can almost guarentee it.
Customer: replied 10 years ago.
Reply to Davo/diablo666's Post: I set the bolts in the cam sprokets as the repair manual advised me to do but do you think that when i pulled the bolt out when installing the chain that the exhaust cam slipped one tooth off. the engine does not blow out thru the intake like its out of time please advise
Expert:  Davo replied 10 years ago.
Did you remove the bolt before the chain was on the pulleys?If so it probably moved.On those engines one tooth won't cause it to blow out the intake or exhaust.It will just idle rough and perhaps not have full engine power.
Customer: replied 10 years ago.
Reply to Davo/diablo666's Post: I failed to mention that when i rev the engine about 2500 rpms it surges
Expert:  Davo replied 10 years ago.
I'll bet one cam is off a tooth.I diagnosed that same condition for another shop before after a head gasket repair.Idled rough and surged at cruise rpm.It would also explain your misfire codes.
Customer: replied 10 years ago.
Reply to Davo/diablo666's Post: will it cause the engine to over heat
Expert:  Davo replied 10 years ago.
It may run hot but shouldn't overheat on you.Is that why the head gasket was done in the first place?You could have an air pocket in the cooling system.
Customer: replied 10 years ago.
Reply to Davo/diablo666's Post: whats the best way to purge all the air out of the system ?
Expert:  Davo replied 10 years ago.
A tool called an air lift.For those that don't have one overfill the coolant tank and run it until hot.Then turn it off it will pull the coolant in as it cools.If it was overheating prior to the repair this may not solve your problem.You didn't answer my question about that.
Customer: replied 10 years ago.
Reply to Davo/diablo666's Post: vehicle was overheating thus causing the head gasket to blow i did replace the thermostat with a new one. when i removed the old head gasket it looks as though someone had put in alumaseal to stop it from leakig also the gasket seems like it was going bad for a long time
Expert:  Davo replied 10 years ago.
I would pull the front cover to recheck the valve timing before I went too much further.I hope you had the head checked for cracks by a machine shop while it was off to make sure it wasn't cracked.If I have been helpful please click on MY accept button.If I have been very helpful you may add a bonus if you wish to do so.
Davo and 3 other Chevy Specialists are ready to help you