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 Curtis B. Your Own Question
Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 27039
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
30244710
Type Your Small Engine Question Here...
Curtis B. is online now
A new question is answered every 9 seconds

I have an Onan p220 in a John Deere 420. It lost power and

Customer Question

I have an Onan p220 in a John Deere 420. It lost power and sounded like it was blowing out of a head gasket or an intake manifold.
What would be your first step to find the problem?
Thanks,
Mike
Submitted: 1 year ago.
Category: Small Engine
Expert:  Curtis B. replied 1 year ago.
Welcome to JUST ANSWER small engines, let me try to help you !! Run a compression test and see if compression is low. That would indicate the head gasket is blown and would show which one is bad
Customer: replied 1 year ago.
Ok, so I will need to buy a compression tester?
Expert:  Curtis B. replied 1 year ago.
You could use finger and rag over the spark plug hole, but it may not be enough resistance to tell which side is leaking. Most auto supplys will loan or rent a compression tester, or Harbor Freight has a cheap one.
Customer: replied 1 year ago.
Ok, then what would be the next step if the compression checks out good?
Expert:  Curtis B. replied 1 year ago.
Loss of power, noise , the spark plug didn't come out? You will have low compression! With head gasket leak , you may be able to feel the gasket leaking if you feel around the heads.
Customer: replied 1 year ago.
I did try that and did not feel any leaks around the heads.
I guess my next step will be the compression test then probably removing the shrouds to check the intake manifolds.
Expert:  Curtis B. replied 1 year ago.
Intake won't cause noise,, but the exhaust manifold will. Let me know what you find. Thanks.