VIDEO 1999 300M 3.5 coolant leak I can't pinpoint please help..

[FastEddie313]

This is my sisters car and it is loosing quite a bit of coolant.. Not good..

It is coming from like the front of both heads where they meet like the backside of the timing cover..

Like right here..


I've been looking under the intake and can't see any wet under there, it's really hard to see anything around this engine..

I'm hoping you guys would know offhand easily what would be leaking for the leak to show itself in these areas, like the water pump or some timing cover O-rings or something..

What do you think guys?

Here, I took a video to make it even more clear..

[cin993]

my vote-- waterpump. at 1m looks like it's dripping from the hydraulic tensioner which is right below water pump on psssenger side.

i'd go rent a coolant system tester... it's free. first clean everything that's wet, blow it off w air to dry, and then pump system up to 17lbs with car off. the leak will show itself easily. i did it and it worked for me.

if you're in there for wp then i'd do the timing belt kit gates is good. god luck

[adu1982]

I second that. It drips right of the tensioner so ....water pump is right in the middle , about just above it.

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[user97]

My guess it is the water pump as well. The timing belt, water pump, idler pulley are most likely past due (100 miles/7 years service interval).

If the belt breaks valve damage will result.

[FastEddie313]

So if the water pump leaks it will fill up the timing cover and leak out the sides there?

[adu1982]

Yes. The cover has a bit of rubber but at this age....and even new i think it lets the water drip out

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[adu1982]

Also it could be from the inner timing cover, cover under the pass cam sprocket. I would change those 3 orings too.

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[FastEddie313]

Also it could be from the inner timing cover, cover under the pass cam sprocket. I would change those 3 orings too.

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Would this be on both sides or just the one? Because it is leaking on both sides..

Do you have to remove the cam pulley from the cam?
Any link to a job description or pics?

[Shawn1301]

To do inner rings the cam pulleys will need to be removed.

I've "borrowed" the tools to properly reinstall the pulleys from a member on the forum. 35 deposit(may vary) and shipping fee covered on my end. Got my job done.

I would do a pressure test as someone said above. Shows true answer without risk of overheating.

System is 16lbs so I'd be hesitant to test higher then that.. but other have with no issue

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[remi]

Hey I'd definitely check those orings. And get Mopar ones, really, there's a difference in size!

This is a picture of my broken 3.5 block. There's an oring for the water pump in the center (the big one) and too small ones on each side.


Basically you have to remove the timing cover, timing belt, water pump, passenger side camshaft sprocket, passenger side rear timing housing. There's a post in the knowledge base (available to premium members, you should really consider joining there are tons of info in there) about the job: http://300mclub.org/forums/viewtopic.php?f=106&t=29099

In a nutshell, it's not an easy job. Camshafts must be locked from the rear of the engine (there is a service cover on each cylinder head). While there, get ready to change those rear cam thrust plate seals as well because they DO leak. Cam sprocket must be hold tight while removing then torquing the cam bolt. Cam sprocket to shaft hole as a D shape with a lot of play hence locking the camshaft... You want to install the sprocket loosely on the cam, install the belt and tensionner, then torque the bolt. Torque is huge (102 Nm / 75 ft.lbs), and the cam locking tools aren't designed to hold so much torque so it's very important to hold the sprocket while torquing the bolt.

[FastEddie313]

I think I'll do a pressure test but I'll need to pull the timing cover and whatever off to be able to tell if its coming from those O-rings or the water pump..

I'm really suspecting those O-rings after seeing that block pic (thanks) because it seems the water is coming out like from behind the rear side of the timing covers about right where the head meets the block..

I can do this job but I'm only home 1 week a month and it's not even my car and I'd be doing it for free..

Do you think it might be worth it to try one of those bottles of "magic" leak stopper for now? Radiator stop leak stuff..
I've never tried one before but this car is pretty much scheduled for an engine/tranny swap or the crusher soon anyway..
200k and the tranny acts up but the breaks and suspension are very fresh and the body and interior arent bad at all other than a blower motor that never stops..
I think I can get a decent powertrain for $300-$600 out of a wreck..

Thank you guys for your very helpful replies..

[adu1982]

Dont use stop leak. I doubt it will stop that.....i detest and hate that crap....just gets your entire system looking like mud with sparkles.....

I can borrow you the cam tools ....just pay shipping...maybe 5 bucks i guess. Rent or buy the few things you may need. Big wrench to hold the cam when torquing (would be too much to ship you mine is heavy and big) and a chrysler puller for the crank pulley (or you can squeze the timing belt through the bottom).
Plenty of info here about it....very doable job....just time consuming.
Trany....chrek it out first (any codes? Maybe a fluid/filter refresh)....my 01 lhs is at 180+ k and you barelly feel it....

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[M-Pressive]

Also it could be from the inner timing cover, cover under the pass cam sprocket. I would change those 3 orings too.

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Would this be on both sides or just the one? Because it is leaking on both sides..

Do you have to remove the cam pulley from the cam?
Any link to a job description or pics?

Tons of how-to documents available to the members of our club. Only $14.95 to join and gain full access!

http://www.300mclub.org/home/membership ... ip-levels/

You will not be disappointed and it will help you get the job done.

[Loki8888]

What was the issue?
I had the same issues and it was the lower planting under the intake manifold. There's two water jackets there. Also there's a huge cavern in the center of the engine where all that antifreeze goes

[Loki8888]

What was the issue?
I had the same issues and it was the lower planting under the intake manifold. There's two water jackets there. Also there's a huge cavern in the center of the engine where all that antifreeze goes

[FIREM]

OLD topic from 2017, OP had External Coolant Leak.
I believe it was the o rings behind the right bank timing cover (behind the water pump)
Coolant filling the valley as you describe is usually the heater pipe o ring in lower intake gaskets.

[In-trepid]

A couple of things caught my attention on this one.
1. Typically, a leaky water pump will present itself as a drip coming from the exact middle of the front of the engine. This is because there is a drain hole at the bottom of the timing belt chamber to allow coolant to drip out the bottom. If RTV was used in the past to seal the timing cover, this hole could be covered and not allow anything to leak out the bottom. I have never seen this, but I suppose it is possible.
2. Leaks around the tensioner usually indicate the rear seals on the timing cover are the culprit.
3. Leaks under the intake manifold are hard to detect for two reasons, but probably in 99% of the cases are caused by either the heater pipe gasket going bad or the heater pipe itself rusting out. The other 1 % is from leaking lower intake manifold to head gaskets. The two reasons that these are hard to detect is the leaks start off small and the coolant tends to drop into the valley and is vaporized by the heat of the engine leaving only a bit of colored residue and nothing leaks out until the leak gets really bad. Second, the engine tends to tilt backwards just slightly and when it does leak, it comes out of the back drain hole and leaks where the engine and transmission join. If leaking here, the coolant is whisked away toward the back of the car when driving and it rarely gets noticed without some reason to look under the car. The leaky heater pipe may also cause the coolant to follow the pipe backwards resulting with a drip in the same area, but this time it follows the top of the transmission back and the same situation occurs. On the rare occasion that the coolant in the valley drips out the front drain hole, it will appear in the middle of the front of the engine the same as a water pump leaking failure.
I have found the easiest way to detect some of these leaks is a borescope camera attached to your cell phone and probing it anywhere you can get access to, but not see clearly.