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Pete, Automotive Mechanic
Category: Medium and Heavy Trucks
Satisfied Customers: 29099
Experience:  Performed various automotive repairs on several light duty and medium duty vehicles over 15 years of service.
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I have a 98 international with a dt466e it has 3 issues not

Customer Question

I have a 98 international with a dt466e it has 3 issues not sure if they are related but it has an oil leak coming from the front cover which I don't think is related but when it heats up it has a misfire when hot I have a feeling it's injector O-rings leaking it loses power and under full throttle it will clear up.... Also if climb in a long grade or hill the coolant will heat up in temperature to about 230?? The cooling fins seem to be clean radiators are all clean but the fan clutch does not kick in noticeably but has resistance what are your thoughts?
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Expert:  Pete replied 1 year ago.
My name is ***** ***** I am a professional here at Just Answer. I noticed that your question had not received a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.My info is somewhat limited on your model here but I had seen no one else has responded and would like to see if I can help here.If at any time you feel that I cannot help with this please let me know. I would have the oil leak checked to see if this is a front cover seal or possibly timing cover gasket as this can be common for this fault here.As for the misfire when warm I would have a compression test done and a block test done to see if you maybe having a leaking cylinder head gasket needing replaced as this can cause an over heat and misfire issue in some cases.It is possible this is injector o rings as well but this may not cause an over heat issue.These need to be checked into/tested further to locate the source of the fault then from there repaired to correct this issue. If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.Thanks Pete
Customer: replied 1 year ago.
Hey thank you for your response yes I do still need help I looked into it further this morning the front crank seal is leaking.. hey thank you for your response yes I do still need help I looked into it further this morning the front crank seal is leaking And also the fan clutch is not engage i blocked the radiators and could not get the clutch to engage up to 225° So I'm guessing that is why it is overheating?
- and the misfire is what I'm confused about it misfires at about 1500 RPMs cruising down the road if you punch it clears up only when it's hot I was thinking injector O-rings but the crank is not long after a Hot restart? What do you think?
Expert:  Pete replied 1 year ago.
Yes,if the fan clutch is not engaging this will cause the over heat issue and fan clutch failure is a common fault here.The test you had done is a good test/check for this over heat issue to see if the fan clutch needs replaced and from the way it sounds from here it does need replaced.The front crank seal leak is common.The seal will need removed after the crank pulley/harmonic balancer is removed and the front of the crank shaft will need checked for any wear as it may need a sleeve put on it and then a new seal installed.This usually requires some special dealer tools to replace this seal.The misfire can be injector o rings or an issue with one of the injectors themselves with what you have described.If you have not had the injectors tested at all I would have this done to see if any issues are found with one or more of the injectors needing replaced.This is one of the more common issues on this model here.It is possible this is the O rings but injector failure is also common and this would need tested further to be sure of the cause. Let me know if you need anything else and feel free to rate my help here. Thanks Pete
Customer: replied 1 year ago.
Thankyou!!! The miss fire is hard to tell its at like 1500 rpm under like no load slight throttle it sounds like it putters but honestly once to give slightest load it clears I almost think it's normal?
Expert:  Pete replied 1 year ago.
It may be normal but I have also seen injectors cause this issue as well as an exhaust leak in some cases.The exhaust leak causes a putter type noise as fresh air enters the exhaust.I would have these checked to see if any of these are an issue here. Let me know if you need anything else and feel free to rate my help here. Thanks Pete
Customer: replied 1 year ago.
Yes it's very odd I almost think it's a transmission related issue it's not shifting on time or correctly what happens is it will knock out of gear and free run under no load and will act like it's misfiring but it's more like a potter because there's no load on the motor what tips do you have on diagnosing those transmissions with issues like that it's an Allison rebuilt as well ?
Expert:  Pete replied 1 year ago.
If it feels like it is slipping when this occurs here like this,this can indicate a fault with the transmission for sure.One of the biggest issues I have seen is debris build up in the transmission fluid.In some cases just having the fluid flushed out/replaced can correct issues like this here.I have also seen issues with the transmission valve body as well needing replaced.If you can I would have this checked/tested further by a transmission repair facility to see if the fault can be pinpointed and repaired.One of these is usually the fault here. Thanks Pete