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Question about ruff idle

2K views 7 replies 2 participants last post by  04mojogt 
#1 ·
We recently installed a Walbro pump in my car. Had a few issues with it but its working fine now. However this issue was happening before i even got a walbro but it only happens every now and then. The problem is.......

Say i go to start my car and usually the Rpm will jump up to like 1500 then idle down like normal. But....Instead of doing that i turn the key and the car starts but the rpm goes to like 900 or so and it just runs really ruff(kinda misfiring sound) then i give it a little gas it revs ruff just like the idle then it goes away and runs fine and doesnt do it again untill a few days later or so. This whole process last for id say 4 or 5 seconds at most. I hope i exsplained it right.

Has anyone ever had this issue before?

Oh yea My Spark plugs were changed less than a year ago.
 
#2 ·
This is exactly what happened to me when the headgasket started to develop a small leak.

I never, during any of the nearly 2 years of having the bad head gasket, saw any smoke from coolant or oil. In the beginning, just coolant was leaking into the cylinder, and causing a detonation type environment. This caused me to go through a sparkplug or two. The leaking occured when the engine cooled down, allowing coolant to leak into the cylinder (3). This caused me to misfire upon startup 80% of the time. As time went by, consumption increased, in coolant and then oil, and so I replaced the headgasket after viewing shine-back in cylinder 3 (fluid in the cylinder).


Is it your headgasket for sure? No.

Could it be? Yes.

Possibly other things, too? Yes.


Just take a look at the pistons through the spark plug wells with a flashlight. If you see the light reflect back, then you have fluid in the cylinder, and that means a new head gasket at some point. (these engines are crazy)

Like I said, I let mine do it for probably too long. Buuuut, she's ok!


Also, how many miles? Have you done the headgasket already? Are you or have you ever gotten any MIL codes? Mine kept creeping up a cyl3 misfire code (0303), but only occasionally.
 
#3 ·
Thank you for Repling. No i havent ever done the head gasget thing. I have 94k miles now. Done the BSR mod and also been ditched the stock header thing loooong time ago. One of my friends told me to try cleaning my Tb which i have never EVER done before ever. However what your saying definatly ill look at. Ill take hte plugs out and look in there. Is there any type of product that i can use that will stop this leak if its not bad? Also i have never gotted a SES light from this ever.
 
#4 ·
If it does turn out to be a leak from the gasket, I would just switch it out. My car has under 82k miles, and I just switched my headgasket, so it's def. a possibility. I didn't see any comparable alternatives to "stop a headgasket leak." To my knowledge, it's nowhere near being like a radiator or other coolant leak...

They are of poor design, these engines. Not quality/construction, just design. There is debate on how to remedy the engine's appetite for headgaskets, alas, I have seen no sure solution.

Probably the best is one of the Ajusa headgaskets.
Import Performance Parts - Import Performance Engine & Racing Parts


I just went with what they had at autozone because it was faster/cheaper. Plus, I don't plan on keeping the engine the same for another 80k miles. ;)
 
#5 ·
Ok i did some physical research today. I took the valve cover off the make sure that wasnt leaking and it was fine. Also the Cams and all that stuff on the top are really clean and brand new looking.

I finally got that Idle relearn to work after i cleaned the Tb out.

I took the sparkplugs out and shined the light down each socket to see what i could find.
And i found in Cylinder 3 a reflection of my light shining. Which means... i have liquid there.
I checked it out and turns out the liquid is Oil. Not Coolant....... Oil. THis exsplains that Misfire when i start it. It leaks in Slowly as it sits. Also notices the top of the pistons are dirty.

Me and my friend seafoamed the car and i thought it would NEVER EVER stop smoking. Was so embarrassing. I also bought some Compression Repair with Ring seal stuff i found in Orielys. Tomorrow after i change my oil im going to add this to the new oil and montior it.

Any other recommendations as to why its Oil and not Coolant? I also stuck a really Long Qtip in there to see what that fluid was and it was Oil.
 
#6 ·
Yes sir, that, unfortunately, is your head gasket.

Your head gasket is the surface between the head and the block. It is designed to seal the two, since they are metal and metal doesn't seal flat against another large piece without something to join or buffer them (gasket).

Our's are metal, where a lot of american and other cars have composite. you need to replace that and the head bolts, since the bolts are tty (torque to yield). This means they are designed to twist to a certain degree when inside the holes, and are one time use because of this.

Anyway, a number of different results can be obtained from a bad head gasket. Leak coolant, leak oil, leak both, into the cylinder, into each other, one or the other, you get the idea. This is because there are a number of these types of passages that run from the block through to the head. Naturally, they both need both.

Ash's guide is pretty darn good.
http://www.b15u.com/sentra-specific...5-change-headgasket-qr25de-altima-sentra.html


May the force be with you!
 
#7 ·
Oh ya,

Good that the valve train is "clean and shiny;" that saves you a lot of cleaning time :)
Pistons being like that is understandable/normal. They should have a carbon-like black appearance after some time. I simply scrubbed it off when I opened it, with engine cleaner. It worked well. I've never tried seafoam, but I don't even wanna :icon16: .



Aaaaaaaand as one final thought my friend, because, well, that's just how cars are:

This could also be the piston rings, which this car is also notoriously famous. I have no idea why this stuff is occurring in cyl.3 so often, but I guess it just does. Usually it happens on the farthest from the oil pump which would be #4...

Like I said, crazy engine :eek13:
 
#8 ·
WEll im still gonna keep a Eye on how it acts now. But i changed the oil and went with a 10w30 this time. I noticed that my oil level was really high. My friend said over filling can cause this issue also with the oil seeping into there. Sooo this time instead of just pouring the oil in there untill it was gone i actually waited and checked the oil level as i did it. Stop it right at the mid way mark. Checked the plugs and stuff like 5 times after ive driven and let it sit and stuff. And belive it or not it hasnt done that missfire at idle since. Not saying this fixed it but so far.... i havent had that issue at all. And it started happening like every time i turned the car off and let it sit for 5 minutes or so after starting it. Hasnt done it at all. So ill give it a few more weeks and i will update and let you all know if this was the issue.
 
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