3.0L V-6 Plymouth Minivan Question

I need a quick opinion -

Would having one cylinder with the compression down 30 to 40 lbs
compared to the other five cause the check engine light to be set on a
1998 Plymouth Grand Voyager minivan with the 3.0L V-6? I can't find
anything else wrong. The mechanic is hesitant to do a valve job becasue
he claims he has seen this before and fixing the compression did not fix
the problem (and turn out the check engine light). He recommended
dumping the van and buying something from another manufacturer (Ford,
Toyota, GM, anything but another Chrysler product). I really trust this
mechanic, so don't say he is a moron.

Regards,

Ed White

 

Misfire cylinder #5 (P0305). This code comes up consistently. I have been
fighting this problem for months. Many things that have been done - Plugs
(three times - the dealer, Western Auto and me) and wires (twice once at
Western Auto and once by me), distributor cap, intake manifold gaskets
replaced, swapped injectors around (misfire stayed the same), O2 sensor (old
one looked bad on the diagnostic scan but there was no code), fuel filter
(needed one). At first the light came on occasionally and sometimes went out
by itself. Later, after I reset it, it would stay out from 1 day to 2 weeks.
Now it comes on after a few miles. The mechanic is concerned that he will be
able to fix the low compression, but not fix the light. He has had similar
symptoms on two other mini vans with this same problem. In both cases he did a
valve job and restored the compression, but the light kept returning despite
an engine that seemed to be running perfectly. In my case, the problem is
always the same (#5 misfire). The van runs OK and has about as much power as
it ever had. I told the mechanic to do the valve job. I think he is worried it
won't fix the problem and I will be mad at him. I think it will fix the
problem and I won't be mad at him even if it doesn't. I think a cylinder that
is 40 lb. less than normal (160 lb. or so) is out of spec. I was taught that
the low cylinder needs to be within 75% of the high cylinder. This is engine
is out of that range. Since I told him to just do it. I guess I'll know if the
problem is solved soon enough.

Regards,

Ed White

 

This is like deja-vue. I've had 2 of these in the shop in the last few
months. As much as your mechanic doesn't want to, pull the heads and do a
valve job. Be sure to check the guides for any wear. I'll even go a can of
Mug rootbeer that it fixes it...

Denny

 

Vlave job should take care of things. The 3.0 is not a favorite of mine but
it has a strong bottom end. The top end is what I don't like but then it's a
mitsushitti. As far as the mechanic telling you to dump it for another mfgr.
tell him to buzz off the attitude but next time get a 3.3 or 3.8. You'll
have a much better product. (I'm a former 3.0 owner), and never again for
me.
Larry

 

Valve guides gone. Put on rebuilt heads, light will stay off. Bottom
end of the MitsoShitty 6 is almost bullet proof.