Another 2001 4.0 P0306 issue
11-01-2010 | 10:32 AM
#16
CF Veteran
Joined: Nov 2008
Posts: 2,003
Likes: 4
Year: 1987
Model: Cherokee
Engine: 4.0
exhaust valve rotation?
that is both a hoax and a joke. valves seat into the head. rotating it will actually make it worse, not better.
where are you located? I could locate and rebuild a head for you AND install it for the cost of a new head, including gaskets and everything.
that is both a hoax and a joke. valves seat into the head. rotating it will actually make it worse, not better.
where are you located? I could locate and rebuild a head for you AND install it for the cost of a new head, including gaskets and everything.
11-01-2010 | 11:33 AM
#18
CF Veteran
Joined: Nov 2008
Posts: 2,003
Likes: 4
Year: 1987
Model: Cherokee
Engine: 4.0
no problem.
it's very easy to rebuild a head. for the cost in tools, plus a junkyard head, you could rebuild it and install it cheaper than the cost of the head.
I just like to try and promote doing things yourself...it's not that hard, and it's nice to know you don't need a shop to fix anything.
it's very easy to rebuild a head. for the cost in tools, plus a junkyard head, you could rebuild it and install it cheaper than the cost of the head.
I just like to try and promote doing things yourself...it's not that hard, and it's nice to know you don't need a shop to fix anything.
11-01-2010 | 11:35 AM
#19
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Junior Member
Joined: Oct 2010
Posts: 31
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From: DFW
Year: 2001
Model: Cherokee
Engine: 4.0
yup, I know what you mean, I have all the tools but not so much time. My 19 yo son is the driver of the Jeep and needs to learn how to do these things... 
...a new head is the easier way for us to go.
He just texted me and said the misfire is getting worse, i.e. more frequent.
...a new head is the easier way for us to go.
He just texted me and said the misfire is getting worse, i.e. more frequent.
11-01-2010 | 11:41 AM
#20
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Joined: Nov 2008
Posts: 2,003
Likes: 4
Year: 1987
Model: Cherokee
Engine: 4.0
eesh. no bueno.
you set proper gap on the plugs, correct?
how does the plug on that cylinder look? whiter or darker than the rest?
I honestly think this could be as simple as a bad injector or bad connector to the injector.
oh, taste the oil (wierd, i know) and tell me if it tastes sweet...
you set proper gap on the plugs, correct?
how does the plug on that cylinder look? whiter or darker than the rest?
I honestly think this could be as simple as a bad injector or bad connector to the injector.
oh, taste the oil (wierd, i know) and tell me if it tastes sweet...
11-01-2010 | 11:50 AM
#21
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Junior Member
Joined: Oct 2010
Posts: 31
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From: DFW
Year: 2001
Model: Cherokee
Engine: 4.0
we rechecked the plug gaps to .035 yesterday...
all new plugs, all showed dry when removed for the gap check and #6 replacement as original #6 was found cracked...
we did wrap the injectors and fuel rail with thermal protection, yesterday...
I have had some concern about the #6 injector wiring but the noid light says it is working... at least when the noid light is connected...
all new plugs, all showed dry when removed for the gap check and #6 replacement as original #6 was found cracked...
we did wrap the injectors and fuel rail with thermal protection, yesterday...
I have had some concern about the #6 injector wiring but the noid light says it is working... at least when the noid light is connected...
11-01-2010 | 12:21 PM
#23
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Joined: Sep 2009
Posts: 1,371
Likes: 2
From: morrisonville ny
Year: 2000 @ 1994 givin away
Model: Cherokee
Engine: 4.0
why bother replacing the head with a 2000/2001 head?
they are known to be poor quality heads, they are known to warp and crack.
the '95 head is ported better, probably the same price, and is cast properly. sure, you have to make a bracket to hold the coil rail/packs, but it's gonna net more power, better mileage, and less chance for failure.
that said, don't drop $150 on gaskets. you need an intake/exhaust gasket ($13), head gasket ($20), head bolts ($36), and t-stat gasket ($3), and a GOOD rubber valve cover gasket (which is NOT included in the $150 gasket set....they include a cork one...)...that is $44.
so, you get the new head, and spend $90 or so on gaskets, and are less out of pocket.
you don't need to pull the fuel rail, sensors, or throttle body off the intake to do this job...
they are known to be poor quality heads, they are known to warp and crack.
the '95 head is ported better, probably the same price, and is cast properly. sure, you have to make a bracket to hold the coil rail/packs, but it's gonna net more power, better mileage, and less chance for failure.
that said, don't drop $150 on gaskets. you need an intake/exhaust gasket ($13), head gasket ($20), head bolts ($36), and t-stat gasket ($3), and a GOOD rubber valve cover gasket (which is NOT included in the $150 gasket set....they include a cork one...)...that is $44.
so, you get the new head, and spend $90 or so on gaskets, and are less out of pocket.
you don't need to pull the fuel rail, sensors, or throttle body off the intake to do this job...
HE'S FINE ,he got his replacement head the same place I did and they state that the process the use fixes all the known problems.I haven't had any problems with the new head in 5 yrs so I think its good just my opinion and the company that makes the heads and has to warrenty them.He'll be ready to ![Name: 93C_peelout[1].gif
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Just so you know yes I've been through it.thanks.( check the cam lobes also)
Last edited by rich; 11-01-2010 at 12:32 PM.
11-01-2010 | 01:54 PM
#25
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Joined: Nov 2008
Posts: 2,003
Likes: 4
Year: 1987
Model: Cherokee
Engine: 4.0
Not if he got an aftermarket head that adds the extra metal to the casting process.This fixes the problem of the weak casting between clyinder 3 and 4 warping is the earlier heads mostly cracking is the mid 1999-00-01 heads but all aftermarkets fix the problem. HE'S FINE ,he got his replacement head the same place I did and they state that the process the use fixes all the known problems.I haven't had any problems with the new head in 5 yrs so I think its good just my opinion and the company that makes the heads and has to warrenty them.He'll be ready to Attachment 28891 Just so you know yes I've been through it.thanks.( check the cam lobes also)
HE'S FINE ,he got his replacement head the same place I did and they state that the process the use fixes all the known problems.I haven't had any problems with the new head in 5 yrs so I think its good just my opinion and the company that makes the heads and has to warrenty them.He'll be ready to Attachment 28891 Just so you know yes I've been through it.thanks.( check the cam lobes also)k. at least it's not OEM quality...that is what I was saying is bad...
11-02-2010 | 05:24 PM
#27
Thread Starter
Junior Member
Joined: Oct 2010
Posts: 31
Likes: 0
From: DFW
Year: 2001
Model: Cherokee
Engine: 4.0
we reset the ecm/pcm... now it runs like crap with multiple misfire codes and loss of power... is this normal for ecm reset?
Last edited by membrain; 11-02-2010 at 08:38 PM.
11-03-2010 | 07:19 AM
#29
Thread Starter
Junior Member
Joined: Oct 2010
Posts: 31
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From: DFW
Year: 2001
Model: Cherokee
Engine: 4.0
Generally seems to run fine until engine heats up... Temp sensor problem now?
Latest codes were multiple misfire detects on 2, 5 & 6 along with a P0352 & a (1391) ignition related code...
rechecked (R/R) all connections on sensors and injectors...
removed coil pack, checked plugs again, reinstalled coil pack... all plugs look like they are firing fine...
added some anti-freeze to radiator as it seemed a little low...
added some seafoam to the crankcase...
will run it today and see what happens.
Latest codes were multiple misfire detects on 2, 5 & 6 along with a P0352 & a (1391) ignition related code...
rechecked (R/R) all connections on sensors and injectors...
removed coil pack, checked plugs again, reinstalled coil pack... all plugs look like they are firing fine...
added some anti-freeze to radiator as it seemed a little low...
added some seafoam to the crankcase...
will run it today and see what happens.
Last edited by membrain; 11-03-2010 at 11:00 AM.
11-03-2010 | 08:45 AM
#30
CF Veteran
Joined: Nov 2008
Posts: 2,003
Likes: 4
Year: 1987
Model: Cherokee
Engine: 4.0
you know that you have to do an oil change now,right?
and, if it's getting a misfire on more than 1 cylinder, it's probably not the head that's the issue.
what's a compression check tell you?
and, if it's getting a misfire on more than 1 cylinder, it's probably not the head that's the issue.
what's a compression check tell you?