[Smackeyacky]

Hey everyone, my first post and annoyingly its bad.

I bought a very cheap 300c 5.7 that i knew had engine issues, but trying to diagnose it.

Basically the engine is sucking huge amounts of air from the crankcase, but not through the PCV. When you rev it, massive clouds of grey smoke come out and the oil filler and dipstick tube are sucking air in.

Never seen anything like it before. Is it possible that the intake could be pulling vacuum through the oil gallery gaskets that go to the oil filler and crank vents?

Or maybe something far more catastrophic? It has me stumped other than maybe taking the intake off and inspecting the gaskets and whatnot.

Any suggestions appreciated.

 

[Smackeyacky]

It sounds like either the intake gaskets are shagged or the piston rings are shagged.

Well let's hope that it's the intake gaskets. I figured if the piston rings were worn you would get blowby, not negative pressure in the crankcase but I'm not familiar with the gen 3 hemi.
The local dealer doesn't have any of the gaskets in stock, are the aftermarket ones any good and where would you normally order them? (In Australia but happy to order from the US).

 

[Smackeyacky]

Welcome to the forum. I'd be surprised if it is the intake manifold gaskets on a 5.7, unless the bolts are very loose. If it were a 6.1, I'd bet that was the problem. ... Also, check to see if the bolts are properly torqued. If you have access to a smoke tester, you can try that too.

OK, the design is different between the 5.7 and 6.1? I think I will pull that manifold and look anyway, I am no sure this engine is original to the car so maybe the manifold has been bodged onto the wrong kind of motor or something.

edit: for a smoke test, is it enough to block off the PCV and air balance tube and see if the smoke is getting into the manifold? If the smoke is getting past the rings or valve guides or whatever what could I do to narrow it down other than maybe pulling a few spark plugs?

 

[Smackeyacky]

What year is the vehicle? Can you see any evidence that the engine has been tampered with or possibly removed? What does the odometer say for mileage? Does it look like it has been properly cared for or does it appear to be neglected? Have you checked for Diagnostic Trouble Codes?


On a 5.7, the PC System and, especially the PC Valve, are one of the biggest weak spots on a 5.7. It's difficult to determine if the valve is good or bad, because the spring in it is so weak to begin with. After time it gets weaker and the old method of "shaking the valve" is not an accurate way of checking them. I've never seen one that didn't shake, no matter its condition. Just change it every 15-30K and be done with it. You'll be able to see how bad the PC System is by looking at the back side of the throttle body butterfly. It'll be all caked up with crud and, worst case, there will be oil puddling in the intake manifold plenum.

The car has been neglected. I have no idea if the engine has been changed but it looks pretty suspicious i.e. obvious home fixes on the wiring harness, EGR removed, wiring not clipped in at various places. Trouble codes on #6 cylinder and oxy sensors (according to a tech who refused to fix it ha ha). I guess the first real step is to remove the throttle body and look inside the intake manifold before pulling it off completely, but it doesn't seem like a huge job.

What would concern me is if they dumped a later motor into this 2005 and incorrectly re-used the intake manifold or something like that. It idles fine and sounds strong, no rattles or anything just volumes of smoke and hesitation when you hit the throttle.

 

[Smackeyacky]

The car has been neglected. ...

I got to start pulling the intake system out today. There is oil pooled in the intake tube before the throttle body, the throttle body itself is pretty dirty. More troubling is the giant pool of oil in the intake manifold itself. I guess I have no choice but to pull that, drain it out and clean it up and then start trouble shooting again.

I noticed today that when you shut the car off, quite a visible amount of vapour comes out of the oil tubes i.e. out of the filler. While it's running it seems to be sucking quite hard at the filler tube which is something I have never seen before. The manifold bolts do seem not terribly tight so I will have a look at the gaskets carefully when I reassemble it.

 

[Smackeyacky]

I got to start pulling the intake system out today. There is oil pooled in the intake tube before the throttle body, the throttle body itself is pretty dirty. More troubling is the giant pool of oil in the intake manifold itself. I guess I have no choice but to pull that, drain it out and clean it up and then start trouble shooting again.

I noticed today that when you shut the car off, quite a visible amount of vapour comes out of the oil tubes i.e. out of the filler. While it's running it seems to be sucking quite hard at the filler tube which is something I have never seen before. The manifold bolts do seem not terribly tight so I will have a look at the gaskets carefully when I reassemble it.

 

[Smackeyacky]

Well, pulled the intake manifold, gaskets do look a bit tired. More worrying is the massive puddles of oil everywhere. At least I know that valve seats nicely!

 

[Smackeyacky]

I think I'd first take a look at the PC Valve and replace it. Have to go now but will be back later.

It just seems like waaaaay too much oil for a PC Valve. I'm thinking valve guides/valve stem steals.

How hard is it to pull the heads with the engine in there? My next move seems like it should be compression test all the cylinders, and if they come up good (which is likely given it runs strong even with the oil getting sucked through it) then pop the heads and do a valve job. Thanks for the pointers so far!

 

[Smackeyacky]

I'm going half way. New pcv ordered and will take a punt and just change the valve seals since its fairly simple and i have the tools handy.

I figure if the guides are bad the seals will still work ok for a few months until i get a chance to pull the heads.

Engine actually looks ok inside, no obvious signs of overheating or damage so far and it runs very quietly, no valve chatter or tick so I think the guides are probably ok.

 

[Smackeyacky]

Don't get too hasty about pulling the heads. Troubleshoot the easy, inexpensive stuff first. Do the compression and, if necessary, the leak down test before you start tearing into things. IMO, this should be the next order of business.
...

Valve guides may be some of the problem, but not to the extent that would cause that much oil contamination. I would also be surprised if the valve seals are bad too, again, unless it has been grossly neglected, been overheated or has a zillion miles on it. The valve seals on my 6.1 with 165K on it were still good. When I changed valve springs on both of my 5.7's (both under 100K), all of those seals were good too.
...

I guess what I'm chasing here is the presence of negative pressure in the crankcase, even when the PCV system is blocked off. It's particularly pronounced at idle (I haven't driven the car more than 150 metres) and the oil sitting behind the valves just seems very high even with the intake cleaned out. Heads are staying on for the moment, should be able to inspect at least one of the intake valve seals today

edit: This tool is the correct one for valve spring compression with the cylinder heads in place?

POW352003 Valve Spring Compressor Tool for Dodge Hemi 5.7L 6.4L

POW352003 Valve Spring Compressor Tool for Dodge Hemi 5.7L 6.4L

www.totalperformance.net.au

I have a generic valve spring compressor and an air compressor (although I think I'll need a fitting that reaches down as far as the spark plug). Was just thinking of carefully locking the intake valve in place with a bit of rubber and a small set of vice grips since I am leaving the exhaust ones alone for now.

 

[Smackeyacky]

Also, while doing the job, plug all the oil drain back holes and bolt holes that are big enough for one of them to fall into.

OK ordered and on it's way - a lot of this stuff is more expensive in dollarydoos unfortunately. Good tip on plugging the holes. For this exercise I'm going to skip the exhaust ones just to shorten the job and test my hypothesis.

Any preferences on valve stem seals? The Fel-Pro ones seem to be readily available here.
edit: very confused now about which ones to order. There seem to be two styles (a "hat" style and a more traditional looking one). Guessing I need to find the engine number to work out what to try and buy or will these work?

https://www.summitracing.com/parts/cwa-53021578aa/make/chrysler/model/300/year/2006

 

[Smackeyacky]

No preference really. The ones in the picture look more "high end" than the ones on both of mine. Mine look the same but don't have the little spring tensioner on the top where it seals the valve stem. The factory ones are like the ones I have on mine. FWIW, when I pulled my 6.1 heads with 165K on it, the valve seals were all still good, pliable and no oil getting past them.

Hmm. I couldn't get the generic valve spring compressor to work on the shrouded valve springs so have to wait for the specialist tool to arrive. If I get the spring off and find the valve seals are good I am all out of ideas. Probably should pop the valve cover back on and proceed with the compression tests. I am trying to order some factory seals but they are confused themselves about which ones fit. I have only ever seen bad stem seals on cars that were abused i.e. no oil changes, no servicing, overheated etc. but that just doesn't look like what I'm seeing on top of the cylinder head which looks about as clean as anything I've looked at over the years.

 

[Smackeyacky]

You really should do the compression check first..... You'll also need a compressor and a way to pressurize each cylinder you're working on.

When I get a chance, the valve cover will go back on and I'll do that compression test. I figure I need to do it anyway before attacking the valve seals to make sure they will hold enough pressure to do the seal replacement.

I did find some suspicious looking RTV around the timing case. Like it's been opened at some stage. The previous vendor (a man who was pretty clearly relieved to be shot of this car) mention something about a cam but I don't see how that could cause negative pressure in the crankcase either, unless they seriously botched something. There is some black gunk on the valve springs. Won't know anything for a few more days.

 

[Smackeyacky]

Not much progress until I get the tools / seals. Filled up the oil ports in the intake manifold today with water to see if they were leaking but no leaks at all so that minor possibility has been eliminated. I'm down to valve seals as the culprit.

 

[Smackeyacky]

Got the valve on #1 exposed, unexpected looking valve stem steal for this year of car. Is there something on the engine that gives an idea of the year? I thought I would see a "hat" style valve stem seal but it looks a lot like the smaller one - it's seriously buggered / doesn't really fit the valve so I'm pretty sure this is the issue, but what replacements are available?

 

[Smackeyacky]

You're right, that's definitely the wrong type seal. The hat type are the correct ones.Can you see any of the others without tearing into it any more? Maybe someone just changed one or two for some reason.

The fun part here is that I have 8 hat style seals (have to wait for the other 8) and there is no way they are going to fit. They won't go down far enough to hit where the valve spring spacer is on this motor. The step you can see under the existing valve seal is waaaaay too big to allow the hat style seal to go on there and even if it did, the brim of the "hat" has nothing to sit on.

I've been digging through photos and thought (maybe) it's a 2009 head but that doesn't make sense since they probably don't work on an early engine. I guess there is the slight possibility the head is a 6.1 unit but if the entire engine was a 6.1 it should have an aluminium intake manifold (at least I think so, it could be an engine from a Jeep for all I know).

I'm going to have to find the cast marks on the head and the block and work out exactly what is going on here.

 

[Smackeyacky]

All of the heads will pretty much interchange. It's pretty east to tell the 09's and the SRT8's from the early ones.

I am looking for pictures of the different head versions, definitely have square intake ports. I have an inspection mirror here somewhere, will go digging for the casting numbers. I ordered some of the later style seals will see what they look like when they show up.

edit: Almost certainly "Eagle" heads, possibly entire eagle motor from a later car. The sticker on the rocker cover is unfortunately torn, can still see a part of the 5.7 designator (well, it says .7 so guessing that's what it is). https://www.dodgegarage.com/news-api/wp-content/uploads/2020/10/005-image.jpg

 

[Smackeyacky]

Still waiting for parts. Nobody has anything in stock, Chrysler dealer said "nothing available" when I rang them out of desperation on Friday and t he comp cams ones I ordered haven't been shipped yet.

Had some more time to play with the car and there is no sound out of the radio at all. It has a basic in-dash cd changer which says it's tuning channels and whatnot but no sound. Tried a few of the tips from this site (disconnect battery, examine fuses) but nothing obvious pops out. Drivers seat leather is completely stuffed but the other seats look like they will come up with a bit of leather conditioner.

 

[Smackeyacky]

Finally, valve stem seals arrived. Will get through them as time allows.

 

[Smackeyacky]

Got it mostly done. If you're going to do this job you will need a few things to make it more convenient:

1. Your cotton rope being used to feed into the cylinder to hold the valves up better be fairly stiff. I kept having to cut sections off the end when it got too "worked" and couldn't be fed into the cylinder.
2. Buy a mechanics magnet to grab the collets. Much easier than trying to remove them with just your fingers. At one point I dropped one was very lucky to get away with it.
3. I used an old TV antenna to judge when the cylinder was at the bottom before feeding the rope in.
4. The collets were stuck on 5 out of 8 inlet valves, required more force than I was expecting before they popped free. I could have used compressed air on the cylinders to hold the valves up but it might not have worked on most of them.
5. Pack rags around the area where you are working to catch any dropped collets.
6. The valve covers are a bit of a mongrel to remove - 8mm bolts on the exhaust side are mostly hard to reach. I ended up using a deep 1/4" socket and swivels/extensions. You need the deep socket because some of the fasteners have exposed thread that is used by the wire retainers.

All in all it was taking me 30 minutes per cylinder with having to retry the position of the rope. I had the skip the exhausts because the tool I bought couldn't be fastened down on the exhaust side without hitting the wheel arches, A/C lines and wiring harness. Overall it seems like the big hemi is fairly easy to work on other than that.

edit: car is buttoned up, still blows smoke. Misfires detected cylinder 6, which at least narrows down the problem I guess. I can now hear it chuffing, so I either bent a valve or isolated the issue. Either way it looks like the heads will have to come off.