Engine problems (3.5l HO in 2000 300m)...

So everything seemed to be running fine on my car, till yesterday. Did my
35km commute back home, and when I got to the lights outside town, the car
was idling really rough. Enough to give the car a gentle shaking.

I got home, turned the car off, turned it back on, same issue. Rev it up,
and it ran smoothly after about 1500rpm, but rough below that. No "Check
Engine" light, tried doing the OBD retrieval, but I don't know if I didn't
get one because I don't know what I'm doing, or because there wasn't one to
retrieve. Have to check into that more later.

This morning, I thought I'd try taking the car to work, see how it did. But
as I pulled out, I noticed a lot more exhaust cloud than I'm used to seeing,
especially at current temperatures. Pulled back into the driveway, and
noticed a fluid spill about 6" in diameter. Felt kind of oily, but it
wasn't engine out (wrong color). Pulled the car into the garage, and
checked the fluid levels, and all seem to be good with the exception of the
coolant level (down, but not too low yet). Ran the car for a bit again,
noticed the exhaust cloud again. Doesn't smell really off, but not really
normal either. Found out the fluid leak is happening at the muffler/exhaust
system connection.

One other reference point is that on the way home, I passed a semi on a two
lane road, so for the first time since I've owned the car (about a month), I
had to really tromp on the throttle. Did pretty good going from 80km/h to
140 though!

So my thought is a blown head gasket, causing a coolant leak. Any other
thoughts or ideas? Any idea how many hours it is to replace that (shop
hours)?

I'll be posting a similar message to the www.300m.org forums, and possibly
the DodgeIntrepid forums. Reply where ever you feel comfortable!

Clint

 

White smoke (i.e. steam) out of exhaust pipe combined with low coolant
level seems to be pretty indicative of coolant getting into combustion
chambers. Rough idle is probably due to the cylinder(s) in which
coolant is getting into not firing. You can probably find out which
cylinder(s) that is/are by pulling out spark-plugs and seeing which
ones look freshly cleaned with coolant (i.e. clean and shiny). That
will give you a good idea on which side of the engine gasket/head/
block is damaged.

Did the oil look whitish/creamy? Often when the head gasket blows,
vapors can get into the oil contaminating it and making it look
creamy.


Thanks,

Alex

 

The oil color was normal.

Clint

 

BTW, thanks for the quick response!

Clint

 

In another forum, someone else suggested checking the plugs, and that the
leak might possibly be an external leak running down the exhaust system to
the muffler. He also indicated I should prepare for a "big bill" due to the
size of the puddle. My notes on that follow:

==============================================================================

How big is a "big bill"? Like engine replacement big, or what? Timing belt
replacement big?

The plugs are new anyway (like a week old), so I'm not sure that they'd be
terribly dirty regardless of a coolant leak or not. I don't think the plug
change should have anything to do with the rough idle, but it could be
related, I guess.

I don't think there's a leak running down to the muffler, as there's no
other leaks under the car in between. And the cloud of smoke was very
white. There was no smell of antifreeze when the heater was turned on this
morning.

I stuck my finger in the overflow tank, and it had the same "feel" as the
fluid at the leak. Kind of oily, but not really. Not water, in any case.
The coolant level was down lower than I thought, but still in the overflow.
There was no overheating at any time (never got above the halfway point of
the gauge), so hopefully that will minimize damage.

Anyway, I just got back from taking the car to the garage, and the guy who
saw me drive in was pretty sure that it was some sort of coolant leak just
from the cloud. Even before he knew why I was coming there. So it's
probably a question of how bad, and how expensive. *sigh* On the hopefully
plus side of things, the local shop has two guys with extensive Chrysler
experience... They did express surprise that this engine would have a head
gasket issue; it wasn't something they'd seen on them in the past.

I'll post back when I get the news. For posterity's sake, if nothing else.
BTW, I'm also due for a timing belt change. The guy at the shop indicated
that doing one at the same time would save on labour. Does that make sense?
If so, at least that's a cost saving... Gotta look at the bright side of
things!

Clint

 

For what its worth, the Chrysler 3.5 is NOT noted for blowing gaskets.
Actually, its not noted for anything bad- its a great engine. The 2.7 on
the other hand... Even if it is a head gasket, its well worth
fixing (fixing RIGHT, including checking the head and block surfaces for
flatness and machining if necessary) and keeping.

You said you haven't had the car long, right? I gotta wonder if the
previous owner overheated it, or otherwise knew the gasket was failing
and unloaded it for that reason.

 

Yeah, the thought of it getting dumped when the previous owner knew about
the problem has crossed my mind... I'll probably drop them a note when it's
all said and done, but I doubt anything will come of it. For all I know,
the head gasket was blown already, and they just dropped in the magic
tablets to try to stop it temporarily. Then when I tromped on the gas to
pass the truck yesterday, it just opened it up again. Who knows... I did
try flooring the throttle a few times when I test drove it, and nothing
happened (besides acceleration). And I have run at least 1500 km's on it
since I bought it, including an 800 km jaunt my wife did with her sisters
out to the mountains.

The shop just called, and they found the #5 plug as "wet", so there's
definately a leak somewhere in there. But until they find out what exactly
it is (gasket vs. cracked, head resurfacing required, etc), they couldn't
say too much *sigh* And they can't find out too much until they pull the
head off, which will be happening shortly. Initial estimate is $800 for the
head gasket replacement. All prices in CDN$. They quoted me $500 on the
timing belt change, and at least half of that was labour, so I'll save that,
anyway.

Clint

 

Have them change the water pump too. Make sure the oil gets changed. Drive
it 100 mi & chanage the oil again!!!

 

You might still be lucky, its remotely possible that it could be a lower
intake gasket and that its sucking coolant in the intake runner. Usually
those leak out externally, though.

 

More details....

There was good news, and bad news. On the good side, there was a
concern yesterday that there might have been a piston/valve collision
as part of the fun. Don't know why they were concerned about that in
particular, but there you go. That didn't occur, and there was no
cracked head or warpage, so that helps.

On the not so good side, it appears that this was caused by a plugged
EGR valve (I think he said) that caused a build-up of pressure. That
caused the head gasket around the #5 cylinder to blow. So there's a
few more gaskets and valves that need to be replaced. But since
everything is yanked apart anyway, it's just a matter of parts cost,
rather than additional labour. They were planning on putting in a new
water pump, and the old one was showing signs of leaking anyway.

Current estimate is $600 for parts, and $600 for labour. Could have
it back as early as tomorrow night, if he can get all the parts in a
timely fashion. I asked him if the previous owner could have tried to
hide the damage to sell it, but he didn't figure that was likely.

Clint

 

I am not sure that EGR valve had much with the headgasket blowing --
headgasket seals the space between the block & the head... It has
passages for oil and coolant... Usually it blows due to the engine
overheating at some point, which forces great stresses on the
gasket... Once microscopic cracks develop in the gasket the rest is
simply the matter of time. Huge pressures created during combustion
force gases into the cracks, and eventually a passage is created
allowing coolant to seep into the combustion chamber...

EGR valve allows exhaust gases to enter combustion chamber for
emission control purposes. Stuck EGR (Exhaust Gas Recirculation) valve
clearly will contribute to rough idle conditions but is unlikely to
cause the gasket to blow...

There was no reason for the shop to think that there might have been a
collision between pistons/valves -- the only way that happens is if
timing belt jumps -- does not really happen on these cars unless they
are WAY over the service interval of 100K mi/160K km

But it totally makes sense to replace the belt/water pump... I have
three LH cars with high milage (3.2/3.5 engines) and I replaced belt/
pumps on all of them... I would recommend swapping out also timing
belt tensioner pulley (it is a $70 CAD part from the dealer). I found
that on 2 of my 3 cars the bearing in that pulley was starting to
go...

BTW, the reason you replace the pump on these cars is because it is
driven by the timing belt... if the pump's bearing seizes then the
belt will jump and you will need a new engine. Same rationale applies
to the tensioner pulley.

Hope this help...

 

Ended up being closer to $1500 by the time a coolant flush was done. Seems
that should have been in the initial estimate, but what do I know. They did
run it for awhile and then do an oil change as well; should I still do
another one in a week or so?

They figured everything else was good, so I should be ok for the next 160K
km!

Thanks for your thoughts and advice, all!

Clint