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Posted: 10/15/2013 7:47:27 AM EST
So mechanical troubles continue, now I have a sticky valve, and one of my cylinders is misfiring.

I had a diagnostic, and pressure test run, other than the valve nothing else seems to be wrong, and the pressure test was good across all 4 cylinders, according to the mechanic who looked at it the problem is just carbon buildup on the valve.

My car sounds like a motorcycle, I smell gas in the exhaust, and the mechanic says this needs to be done right away as breakdown is imminent, how right is he? money is very tight right now, and I just can't afford an expensive repair, can this wait a couple months, or at least a few weeks? Is there a simple fix I can do myself to clear the carbon buildup?

How much should this repair cost?

Vehicle is a 1999 Dodge Neon. Engine is the 2.0 liter single overhead cam.
Link Posted: 10/15/2013 7:49:16 AM EST
I would take off the valve cover and look for the "sticky" valve first.

Should notice more wear on the stem. Either way, its best to know what condition everything is in before you take it anywhere.
Link Posted: 10/15/2013 7:50:48 AM EST
Seafoam.
Run it through a vacuum line and it should clear it up.
Link Posted: 10/15/2013 7:52:08 AM EST
[Last Edit: 10/15/2013 7:54:32 AM EST by victor3ranger1]
Seafoam and you can also use Marvel Mystry oil, 1/2oz per gallon in the gas.



If you use the Seafoam thru the vac line, make sure you have a new set of spark plugs and change the oil and filter after. I usually use the sea foam thru the power brake vac line, go slow and keep it running, put a small amount at a time until it is all used up.
Link Posted: 10/15/2013 7:55:06 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By victor3ranger1:
Seafoam and you can also use Marvel Mystry oil, 1/2oz per gallon in the gas.
View Quote


This. Ive read a lot about using marvel mystery oil to solve this problem. Ive also read about using kerosene in the crankcase. Good luck.
Link Posted: 10/15/2013 7:55:28 AM EST
Originally Posted By S_A_C:
Vehicle is a 1999 Dodge Neon.
View Quote


This, right here, explains it all. I kid. I know a little about working on cars, change brake pads/rotors, done some suspension work, oil changes, etc, but never any engine work. I would not recommend working on an engine yourself especially if you have never done it before. Shit can go wrong in a hurry & you can toast it. I'm honestly not even sure where you would take it to get fixed. Shops sketch me out & i've seen some shops first hand fuck up motors. I own a sports car & would only trust it to a highly recommended tuning shop for engine work, not sure if they would work on a neon.

What is history of car like, any wrecks, what is mileage, are you original owner? Mabye some Lucas product put in your gas tank may help remove carbon? I run a bottle with a full tank every few months.
Link Posted: 10/15/2013 7:56:51 AM EST
The valve is sticking for a reason(s). Could be worn stem, guide, or weak spring. Guess what happens if the valve drops in the cylinder? Google this.
Link Posted: 10/15/2013 7:58:13 AM EST
Seafoam (or a similar carbon buildup cleaner) is definitely worth trying. Get the engine up to operating temperature first, put it in through a vacuum line or by slowly running it in to the intake (watch youtube videos) & let it sit for a while. Drive the daylights out of it for a couple miles after you do it - and maybe repeat for good measure.

I've used seafoam with good experiences before, I know there's also a GM carbon buildup cleaner that's very effective as well.
Link Posted: 10/15/2013 7:58:39 AM EST
[Last Edit: 10/15/2013 7:59:26 AM EST by Silver_Surfer]
BG44K

and WFO!
Link Posted: 10/15/2013 8:01:19 AM EST
[Last Edit: 10/15/2013 8:02:07 AM EST by ar2de]
Pull the head. Knurl the guides (or install new guides), do a valve job and install new valve seals. Should fix it.

Shit in a can doesn't fix worn parts.
Link Posted: 10/15/2013 8:01:32 AM EST
Pull the head and fix it properly. In line four cylinder engines are basic and pulling the head should be straightforward. Take the head to a machine shop and have it inspected for warpage and rebuilt. A good shop will know what to do.
Link Posted: 10/15/2013 8:01:34 AM EST
Seafoam... pull the brake vacuum line and suck it up 1/4 the bottle slowly so you don't stall it out. Then pour about 1/4 bottle into the manifold, the rest into gas tank. Let sit for 15 to 20 minutes, then start and let idle until heavy smoke is gone, then rev up to under 4k rpm's to clear more smoke, then drive around a bit.
Link Posted: 10/15/2013 8:03:39 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By ar2de:
Pull the head. Knurl the guides (or install new guides), do a valve job and install new valve seals. Should fix it.

Shit in a can doesn't fix worn parts.
View Quote


I would, in no way, knurl the guides unless you plan on selling it and want to let someone else deal with it down the road.

Replacing the guide is the only real option here if the guide is worn out of spec.
Link Posted: 10/15/2013 8:04:36 AM EST
You could try the Seafoam treatment through a vacuum line. Chances are it will need a head removal and overhaul to completely cure.
Link Posted: 10/15/2013 8:04:49 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Silver_Surfer:
BG44K

and WFO!
View Quote


BG 44K is great stuff but it can be hard to find, depending on where you live. Seafoam is much more universally available.
Link Posted: 10/15/2013 8:06:22 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By wildearp:
The valve is sticking for a reason(s). Could be worn stem, guide, or weak spring. Guess what happens if the valve drops in the cylinder? Google this.
View Quote

I had a Honda Civic that got a little too hot and was carboned up so bad that the intake valves stuck open resulting in lost compression.
Pulled the head and popped the valve springs off and pulled the valves.
Picked up a head set for it and 2 cans of WD40 and went to work cleaning the head.
Back then it was ~$75 and a full Saturday but I drove the car 600 miles the next day.
Link Posted: 10/15/2013 8:09:57 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By wildearp:
The valve is sticking for a reason(s). Could be worn stem, guide, or weak spring. Guess what happens if the valve drops in the cylinder? Google this.
View Quote



This guy is on to something... Carbon couldn't build up if it was closing with appropriate pressure on the same spot all the time.

I have a photo of what happens when a valve makes it to a piston somewhere.
Link Posted: 10/15/2013 8:21:06 AM EST
Get your mechanic to fix it. He's right - you don't want to wait until the valve hits the piston.
Link Posted: 10/15/2013 8:43:11 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By LurchAddams:
Get your mechanic to fix it. He's right - you don't want to wait until the valve hits the piston.
http://static.ddmcdn.com/gif/camshaft-damage.jpg
View Quote

That is virtually impossible in the 2.0 Chrysler SOHC. See, that is a picture of a 2 valve per cylinder engine and it looks like a diesel engine too. See the flycuts for the valves? Looks very similar to a VW diesel . Which have a single overhead cam design. Since the image is titled "camshaft-damage.jpg", it is probably from a failed tappet since they also have direct acting tappets (no rocker arms). When tappets fracture, they often jam the valve open and in a diesel, this is very bad since a 17:1 compression ratio or greater means no room for the valves at TDC.

With a stuck valve in a gasoline engine, the most damage you can have is a bent valve. In a diesel engine, the valve head will break off and get wedged in the 0.020" space between the piston and cylinder head. That is what breaks pistons like what is shown in the picture . Been there, fixed the damage (back in 2007) and the car is still running. Root cause was improper dealer service when the first timing belt was replaced.
Link Posted: 10/16/2013 9:39:45 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Keith_J:

That is virtually impossible in the 2.0 Chrysler SOHC. See, that is a picture of a 2 valve per cylinder engine and it looks like a diesel engine too. See the flycuts for the valves? Looks very similar to a VW diesel . Which have a single overhead cam design. Since the image is titled "camshaft-damage.jpg", it is probably from a failed tappet since they also have direct acting tappets (no rocker arms). When tappets fracture, they often jam the valve open and in a diesel, this is very bad since a 17:1 compression ratio or greater means no room for the valves at TDC.

With a stuck valve in a gasoline engine, the most damage you can have is a bent valve. In a diesel engine, the valve head will break off and get wedged in the 0.020" space between the piston and cylinder head. That is what breaks pistons like what is shown in the picture . Been there, fixed the damage (back in 2007) and the car is still running. Root cause was improper dealer service when the first timing belt was replaced.
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View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Keith_J:
Originally Posted By LurchAddams:
Get your mechanic to fix it. He's right - you don't want to wait until the valve hits the piston.
http://static.ddmcdn.com/gif/camshaft-damage.jpg

That is virtually impossible in the 2.0 Chrysler SOHC. See, that is a picture of a 2 valve per cylinder engine and it looks like a diesel engine too. See the flycuts for the valves? Looks very similar to a VW diesel . Which have a single overhead cam design. Since the image is titled "camshaft-damage.jpg", it is probably from a failed tappet since they also have direct acting tappets (no rocker arms). When tappets fracture, they often jam the valve open and in a diesel, this is very bad since a 17:1 compression ratio or greater means no room for the valves at TDC.

With a stuck valve in a gasoline engine, the most damage you can have is a bent valve. In a diesel engine, the valve head will break off and get wedged in the 0.020" space between the piston and cylinder head. That is what breaks pistons like what is shown in the picture . Been there, fixed the damage (back in 2007) and the car is still running. Root cause was improper dealer service when the first timing belt was replaced.


So your saying I can probably get away with waiting a little while?, that my engine will not just stop working at any moment?
Link Posted: 10/16/2013 9:42:48 AM EST
When will a light bulb burn out
Link Posted: 10/16/2013 9:47:24 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Dagger41:
Seafoam.
Run it through a vacuum line and it should clear it up.
View Quote


This...don't do it in an apartment complex or somewhere else where smoke is an issue....
youtube and see what I mean.

But do it.
Link Posted: 10/16/2013 9:47:41 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By S_A_C:


So your saying I can probably get away with waiting a little while?, that my engine will not just stop working at any moment?
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By S_A_C:
Originally Posted By Keith_J:
Originally Posted By LurchAddams:
Get your mechanic to fix it. He's right - you don't want to wait until the valve hits the piston.
http://static.ddmcdn.com/gif/camshaft-damage.jpg

That is virtually impossible in the 2.0 Chrysler SOHC. See, that is a picture of a 2 valve per cylinder engine and it looks like a diesel engine too. See the flycuts for the valves? Looks very similar to a VW diesel . Which have a single overhead cam design. Since the image is titled "camshaft-damage.jpg", it is probably from a failed tappet since they also have direct acting tappets (no rocker arms). When tappets fracture, they often jam the valve open and in a diesel, this is very bad since a 17:1 compression ratio or greater means no room for the valves at TDC.

With a stuck valve in a gasoline engine, the most damage you can have is a bent valve. In a diesel engine, the valve head will break off and get wedged in the 0.020" space between the piston and cylinder head. That is what breaks pistons like what is shown in the picture . Been there, fixed the damage (back in 2007) and the car is still running. Root cause was improper dealer service when the first timing belt was replaced.


So your saying I can probably get away with waiting a little while?, that my engine will not just stop working at any moment?


Until the sticking valve causes other problems. I just replaced a set of heads after my engine blew a head gasket. I knew there were problems brewing but I tried to delay the repairs. It's always best to fix the problem asap. Waiting may lead to you being stranded, and if this is a primary vehicle can you afford to be without it?
Link Posted: 10/16/2013 9:49:20 AM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By OrARGB:


This...don't do it in an apartment complex or somewhere else where smoke is an issue....
youtube and see what I mean.

But do it.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By OrARGB:
Originally Posted By Dagger41:
Seafoam.
Run it through a vacuum line and it should clear it up.


This...don't do it in an apartment complex or somewhere else where smoke is an issue....
youtube and see what I mean.

But do it.


Let it sit over night .
Link Posted: 10/28/2013 3:30:51 PM EST
Looks like it wasn't the valve after all. I took it to another mechanic, and he traced the problem to a bad fuel injector, a clogged fuel rail, and a broken wire in the wire harness. $200 Later the cylinder is firing normally.
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