Problems with 1998 Grand Voyager Check Engine Light - The saga continues

For six months I have been trying to help my SO fix her mini-van. The
mini-van is a 1998 Plymouth Grand Voyager, 3.0L V-6, Automatic with
around 128,000 miles. Several months back, her check engine light
illuminated, however the car ran OK and the mileage seemed "normal."

Round One - Local Dodge dealer performed a "tune up." Mostly new new
plugs. Light stayed out for a few days.

Round Two - Local Western Auto replaced plugs and wires. Light stayed
out for a few days.

Round Three - Western Auto Again - replaced plugs again. Light was out
for a few days.

Round Four - yours truly - Used ignition switch method to trigger code
read out." Got code 43. Checked coil resistance compared to manual,
decided it was not quite right, so I replaced it. Disconnected battery
and the light stayed out for almost a week.

Round Five - Used code reader and got P0300 and P0305 codes (random
misfire and misfire on #5 cylinder). Checked plugs, they looked fine. I
decided that maybe the plug wire was not on correctly. Reset light. THe
light stayed out for almost a week.

Round Six - Same codes as before. Replaced wires and #5 plug. Reset
light. Stayed out for a couple of days.

Round Seven - Same codes as before plus P0306. Decided problem might be
leaking intake manifold gaskets, so I replaced them. Reset the light and
it stayed out for about three days.

Round Eight - P0300 and P0305 Codes again. In desperation I replaced
Plug #5 with another brand NGK and replaced the O2 Sensor with a genuine
Chrysler Part. Light stayed out for 3 days but the vehicle did not
complete the OBDII Driving Cycle.

Round Nine - Dodge Dealer again. Same Codes. Dealer performs compression
test and says the compression is fine. Performs a Leak Down Test and
says based on this test, the engine is shot and should be replaced - for
$4,000.

Round Ten - HELP!

$4,000 is a lot to but into this van. It is only worth around $4,500 in
good condition. I am suspicious of the diagnosis that the van needs a
new engine. It runs OK. Not perfect, but no oil usage, no smoke, idle is
little rough, but runs smooth at speed. P0305 code usually shows up with
a couple of days after resetting the computer. I have certainly driven
vehicles that run worse. If I leave the code reader connected to the
engine, I never see the mis-fire condition. The problem is almost always
the same P0300 along with P0305. Once P0306 was also found, but this was
a typical. Not fixing the problem is not an option since this is an
OBDII Inspection area.

I am willing to try miracle cures......

Regards,

Ed White

 

You say you replaced the coil, but it might also be a problem with the
ignition module itself (I'm assuming that's a separate component on this
engine).

It's possible there might be some mechanical problem like a burnt valve or
something that's causing a miss, but the dealer's engine replacement
recommendation seems a tad extreme. Did they provide details of the leakdown
test results?

 

Has anybody tried testing for a leaking intake manifold gasket?

--

 

I replaced those - no effect.

Thanks for the suggestion.

Regards,

Ed White

 

Unfortunately no. They just said based on the results of the test, they
recommended an engine replacement. We don't really care if the van runs like new
- we just want to cure the miss so the Check Engine Light stays out. As far as I
can tell, the van runs about as well as it ever did. The van does have a
persistent click at idle when cold. This click has been with us for a long time.
I assume it is a noisy lifter (if you can use that term for this engine). It
usually clears up as soon as the engine warms up. It did this long before the
check engine light became a problem. The miss is defintiely not continuous. I
have riden for miles with the scan tool attached and never seen it show up.

Thanks for the suggestions.

Regards,

Ed White

 

My best advice (This coming from a guy who bought and still have a 78
Chysler Cordoba) Get rid of that problem Chysler product don't do as I
did!!!!!!!!!!!
ronm

 

it needs a valve job, compression spec is 175 psi and it better be dam close
to that( with in5 psi) or it will set a misfire light. option 2 remove bulb
from lite

 

Well the vehicle has needed almost no maintenance for 120,000 miles. Until the
check engine light problem, it has only needed a belt tensioner replaced.
Otherwise it has been a reliable if deadly boring vehicle.

Regards,

Ed White

 

Hello
I think you need to find another tech to work on your Van. All the
technicians who worked on your Van did not do one important test. It
is Fuel system delivery and control test (ie: Fuel pressure, fuel
volume flow, injectors flow, injector balance, fuel quality). All of
following problem will cause the PCM to set misfire code: Bad fuel
pump (low volume, air bubble), restricted injector(s), dirty fuel
(water contaminated or rusty fuel tank ...), high carbon deposit in
combustion charmber (use borescope to check), poor #5 injector wiring,
leaking at injector and a lot more.
I would do injectors cleaning (prefer MOTOR VAC service) and Engine
top cylinder cleaning first the recheck.

Tree

 

That is not the Check Engine light.

 

If you have the diagnostic tool, why don't you just flush the codes before
going to inspection?

 

I don't know where you are but in California Clearing the trouble code
to turn off the check engine light before going to smog inspection
will most likely fail the inspection test (OBD II monitor test)

 

Becasue the OBDII Inspection program is not that naive. The PCM requires that
a driving cycle be completed before the vehicle is ready for inspection. So
far we have not been able to "flush" the codes and have them stayed flush
before all the readiness monitors have completed their cycles. I think it is
the EGR cycle that takes the longest, and the PCM always sets the misfire code
before that cycle is completed. My scan tool is clever enough to monitor the
cycles, but not so clever that it can fake them out.

Regards,

Ed White

 

I think the OBD2 3.0 liter Mitsubishis are susceptible to
carbon caked intake valves causing missfire codes.
It might be worthwhile to have the intake removed and the
valves and runners Walnut shell blasted like (IIRC) was
necessary on some of the European imports (BMW?) a few years
ago.

 

Thanks for the response. I have heard that this was a problem from others. Is there
any possibility that some additive might "fix" this problem without removing the
intake manifold <again>. I am surprised that the dealer did not mention this option.
I guess they thought we needed a new engine <sigh>.

Regards,

Ed White

 

You can clean the combustion chamber by injecting transmission fluid into
the PCV valve; metered just enough to keep it from stalling at fast idle.
Plan on putting in fresh plugs after the treatment. I don't know if it will
solve your problem. Also, go back to stock plugs if any of the newer
"miracle" plugs have been used. Hotter heat ranges may cause detonation.
Try going to a lower heat range plug if you suspect the misfire is caused by
pre-detonation due to too hot of a plug for the current state of air to fuel
ratio.

 

And this little trick is not going to adversely affect the Oxygen
Sensor or the Catalytic Converter???

 

Back in the days of carbs, we used to pour water down the carb to get rid of
carbon build up. especially when we were going to rebuild the engine. Also
put a couple quarts of ATF in the crankcase and ran it about 100 miles.
Wouldn't believe how clean the engine was when we tore it down after this.

 

Water injection? The only engines I've seen there were CLEAN inside
had head gasket leaks and.....

 

They are succeptible to a whole lot more than that. Dropped valve
guides were common in the earlier years, and valve guide wear is still
a problem. At about 90,000km the heads on my New Yorker were replaced
under warranty due to a couple dropped guides. At about 190,000 I had
to replace the heads again due to worn guides causing oil consumption
and killing the cat. New heads and cat passed emissions just fine -
and again this year at 240,000km.
Darn MitsuShitty engines!!!