1998 Isuzu Rodeo Question codes P0300 P1171 p137

CURTP

MEMBER
1998 ISUZU RODEO
6 CYL
2WD
AUTOMATIC
120,000 MILES

This car is used only when my kids come home from colledge so it sits for 4 months at a time last time it ran ok the ac compessor seized that was repaired and as I took car for test drive the engine started missing badly went back home and did tune up same problem did compression test all cyl. 130 psi except #6 218 psi assumed exaust valve not oppening so pulled valve cover cam lobes seem fine lifters go up and down im at a lost could the exaust manifold be plugged? Help thanks curt

5 Replies

RACEFAN966

MECHANIC
5,029 POSTS

Well it seems strange that one cylinder would be so high and not the rest. However have you checked the timing to make sure that the belt didn't skip a tooth? If not make sure all the marks line up. Let me know what you find.

SPONSORED LINKS

Was this

answer

helpful?

Yes

No

Friday, May 8th, 2009 AT 9:10 AM

CURTP

MEMBER
4 POSTS

Used hose in the spark plug hole and got air at the tail pipe any suggestions? Timming checked out ok

Was this

answer

helpful?

Yes

No

Sunday, May 10th, 2009 AT 9:13 PM

RACEFAN966

MECHANIC
5,029 POSTS

Ok but do you know that both valves were closed when you put air to the cylinder? If so then I would look for a burnt exhaust valve.

Was this

answer

helpful?

Yes

No

Monday, May 11th, 2009 AT 7:16 PM

CURTP

MEMBER
4 POSTS

I was checking to make sure the manifold wasnt plugged and that the valves were oppening. Set cam lobes on exaust to open valves. Could I have carbon build up on 1 cylinder? Old plug showed normal. If it is a carbon build up can you reccomend product to pour down the spark plug hole so I can let it sit and dissolve? Thanks

Was this

answer

helpful?

Yes

No

Monday, May 11th, 2009 AT 8:08 PM

RACEFAN966

MECHANIC
5,029 POSTS

Well it is hard to say what will acually work. However with air coming out the exhaust I would have to assume that either that exhaust valve was open or burned or cracked most common. It could be that there is carbon build up but that would mean that the car is drove only short distances and never really warmed up. I drive my car only a mile or so to work so once a week I get it out on the highway and get it up to highway speed and well warmed up. The only thing that I could recomend to help that you could put straight into the cylinder is seafoam. As far as what I would put in the gas tank and oil would be Z-Max. Let me know what happens.