Oil Light Flicker - 2001 Intrepid 2.7 L

Since there have been many posts here about this problem I thought I'd
relate my recent experience (Dec 28/05).

2001 Intrepid 2.7L V6 ("R" code engine) with 220,000 Km (136 K miles).
Oil/Filter changes every 5000 km (3100 miles). Oil has been 5W-30;
either Valvoline Maxlife or various brands of "Full Synthetic". Oil
Filters have been NAPA Gold (Wix) and occasionally Purolator and Quaker
State.

For the first time ever my Oil Pressure warning light started to
flicker when the car was idling, in gear and not moving. Like all the
other reports of this in the Archives, this happened only when the car
was fully warmed and generally after exiting a highway and coming to a
stop. Knowing the checkered history of this model of engine, having
the low oil pressure light come on is enough to give you the Heebee
Jeebies.

When I took it into the Chrysler dealer to have it checked, they not
only recommended the replacement Oil Pressure Switch, but also the
modified wiring harness per TSB 08-36-99. I had both done. This is
important because a relative of mine had exactly the same issue with
the same car/engine a year ago and the dealer did not seem to be aware
of the TSB, and just replaced the switch ("oil pressure sensor").

The original Oil Switch was indeed leaking internally quite badly and
this is what causes the false low oil pressure warning at hot idle.

I also had the dealer check the actual oil pressure at idle and at 3000
RPM before he installed the new sensor. Results :

Idle Oil Pressure : 32 PSI (recommended minimum = 5 PSI)
3000 RPM Oil Pressure = 87 PSI (Spec = 45 - 105 PSI)

The engine would *not* have been at full normal operating temperature
when this was measured.

Total cost was one hour labor plus about $60 in parts.

FYI folks

Phil

 

Your information is correct. The "wiring harness modification" is
nothing electrical. It is merely warding off future light flickering
problems should the new oil pressure switch start leaking internally.
IOW, the immediate fix is replacing the leaking switch, with the harness
mod strictly to avoid the problem in the future when/if the new switch
ever starts leaking.

That harness modification simply is installing a wire and terminal in
the second (unused - presently sealed) terminal hole in the connector
cavity that plugs into the switch. The distal end of the wire is not
connected to anything. What, you may ask, does that possibly
accomplish? Answer: Absolutely othing electrical. What it does is vent
or relieve any build up of pressure in the otherwise sealed mated
connector cavity. Without the vent, if the oil pressure switch starts
leaking oil, the connector cavity becomes pressurized, and therefore
throws the trip point of the switch off. That is because the system
pressure works on one side of a diaphragm to actuate the switch (turn
the light off). Pressure on the opposite (conector cavity) side of the
diaphragm cancels that amount of system pressure from the actuation
(opening) of the switch, so the switch "thinks" the system pressure is a
few psi lower than it actually is. Hence the light will light at the
worst case conditions (warm, low rpm, i.e., at idle and in gear) when
the system pressure is actually well within spec. (as you found out).

Now you understand why my responses to people on this is to replace the
switch and possibly have the pressures verified for peace of mind. In
the past, I generally haven't mentioned the addition of the wire
terminal/vent (which is what the TSB calls it) because the dealers
charge $20 to $25 just for the part that should be no more than $2 (it
is literally a normal $0.05 piece of small-gage stranded harness wire
with a normal $0.05 terminal crimped onto it. Nice that the customer
has to pay such an inflated price to fix a design problem.

In the future, when people post with the flickering oil pressure liight
problem, I will try to at least mention it - the person should be able
to make the decision. But the vent wire does nothing if the new switch
doesn't leak.

**Oh - by the way - if the $60 the dealer charged you for parts is just
the oil pressure switch and the vent wire, they gouged you big time.
Full dealer list on the two parts is $13.50 and $24.26 = $37.76.**

Glad to see you getting good service out of your 2.7. Mine now has
155+k miles on it, and is running great.

I guess we both have to decide whether to replace our timing chains and
water pumps any time soon, eh?

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

You're right about getting gouged Bill. Bear in mind that these are
Canadian prices. The sensor was $23.15 and the wiring harness was
***$35.00***. This is one of the few times that I didn't mind paying
because the relief of finding out that the alarm was false (and a
$6000+ engine replacement was not on the horizon) far outweighed the
cost.

But let me tell you, I did considerable dickering with them over the
proposed labor charge. First, their computer said 0.5 hours for
replacement of sensor. All in all, I could accept that. Then the
technician said 0.75 hours for the wiring harness to which I replied
out loud : "no frickin' way it takes that long for that crummy little
mod". And then he wanted another 0.5 for the oil pressure check with
the gage. Total they wanted 1.75 hours for everything. Again, with a
few customer's looking on, I told them they were over charging because
the cost removal of the old sensor and installation of the new one was
being charged for over again in the other 2 procedures. After a little
grumbling the Service Manager said 0.75 hours for everything to which I
said 'OK'.

Ahead of time, if I had had my own gage, a fitting and knew what the
thread size for the sensor was, I would simply have bought the
sensor, replaced it myself and checked the oil pressure at the same
time. But when you're worried that the sensor could actually be
telling the truth (low oil pressure), there's no time to screw around.
Take it in, get it checked/fixed, and pay.


Phil

 

Quote :
Glad to see you getting good service out of your 2.7. Mine now has
155+k miles on it, and is running great.

I guess we both have to decide whether to replace our timing chains and
water pumps any time soon, eh? "
************************************************************************************************
Jeez, I've been thinking about that too lately Bill. It's such a game
of Russian Roulette with these engines. If I wait for the water pump to
actually show signs of needing replacement, I risk the potential of
having coolant leak right into the crankcase, or possibly seizing and
thereby destroying the timing chain and therefore the majority of the
engine. If I catch the pump in time, then I can have it plus the chain
and the tensioners replaced all at the same time. But at a cost of $1K
+, it's not the sort of thing you really want to do until it is
needed. It's a tough call.

Phil

 

Just one of the reasons I really don't like the timing chain/belt driven
water pumps... early pump failure can destroy an engine in very short
order!!

Much nicer outside where they are easy to change and just leak on the ground
!!

 

But then the weight would be 3.2341264627773356 pounds heavier and the
cost of the vehicle would be $14.0985928758290745908 higher. That would
put them at a marketing disavantage.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

My 1998 Intrepid, 2.7 has 255000 km on it. I did replace the oil pressure
switch. After reading up on the engine on the internet was scared to death
when the light started coming on.
My mechanic said he could see no sign of sludge and suggested we replace the
switch for $23 + 0.5 labour (His labour is $67 an hour) so it was all done
under $70, that was a year ago. The car runs beautifully.
The timing chain/ water pump argument is, as you say, a difficult one.
The car is probably at resale only about $1500 taking into account
reputation of the 2.7 and the high mileage. So $1000 + on a timing chain
/water pump deal is a bit expensive. However the other side of the coin is
that I would have to spend about $15,000 for a car as comfortable, smooth
and reliable (Yes I did say reliable) Ive done most of the easier work
myself, including replacing a cam sensor and various belts. The only major
problem was the steering rack 'splitting' and one tranny 'limp home' event.
Both of these were covered by warranty. I am seriously thinking of buying a
used Intrepid 2002 or so for about $9000 (CDN). I just wish there were some
official Chrysler service bulletin on how to predict a sludgy engine.
Keith

 

Keith,

I agree - this is a very smooth, comfortable, nice driving car. Even
with 220,000 km, the engine idles and runs so smoothly that I'd swear
it was just built last week. Truly amazing.

As far as the economics of the car go, I'm looking at it the other way.
The resale value is low due age, mileage and reputation of the 2.7 L
engine. Mine is probably worth only $3K - $4K I would guess at this
point. As you say, it would probably cost a good $15K to get something
used but much newer to replace it. So I figure that for a bit under one
tenth of that amount, I could have the water pump, timing chain and
tensioners replaced, and I still have a nice driving, good looking
comfortable car to drive that is now free of worry about those critical
parts (for another 200K - 300K kms). Even if the transmission goes and
needs rebuilding (say another $2500 ?), I still have a good car and I'm
still $11,500 in the good compared to having bought a newer car. This
assumes the car is otherwise in good shape and you aren't tired of
looking at it and driving it. I've been driving Intrepids for about 13
years now (this is my 5th or 6th one - it's mine - the others were
company cars) and I still like 'em.

There's no Chysler bulletin on prediciting a sludgy engine that I've
ever heard of. If I bought another one at a good price and I didn't
have to drive it right away, I'd pull the valve covers and the oil pan
for a thorough inspection and mechanically/chemically desludge it if
needed (if it was a 2.7). If it was a 3.5 (which does not have the
same sludging problem as the 2.7L) I'd probably just de-sludge it for
good measure using Auto-RX without actually pulling any covers for
inspeciton.

Phil

 

I have concluded that the sludgicity of a given sample of the 2.7 is
determined by a combination of 3 things:
(1) The type of driving (short trip stop and go, or mostly highway)
(2) Oil and filter change maintenance (intervals and oil/filter quality)
(3) Other precautions sensibly done (preventive - or corrective if
bought used) - such as synthetic oil or a sludge-preventing additive.

I can't prove any of the above, and who can say which one or two of the
three are the most important, or which one or combination of any two of
the three would be needed to guarantee non-harmful levels of sludge.

IOW - if yours has done well up to this point, and nothing changes
drastically related to the 3 criteria, there is absolutely no reason to
expect it to suddenly start to form sludge.

If the car is 2000 or earlier, there is a fourth thing that you can do -
you can replace the PCV valve tubing with a later version that steals a
little heat from the cooling system to prevent condensation and
solidification of blow-by. That hose without that heat exchanger is
very prone to totally clogging, and a rubber elbow actually dissolves.
The newer part (used starting in 2001 MY IIRC) is drop-in plug-n-play in
place of the original plumbing. I think it's around $45 from the
dealer. I put it on mine. Yours is 2001, so it should already have it.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')