Tarzan

I completely got rid of knocking, that spoiled my ride for a couple of years. The EGR valve cleaning with AC Delco 'Cleans' did the trick. She is very nimble and when I hit the gas on the upgrades she purrs and pulls ahead.

tripleGmax

iTrader: (8)

i might have to look into that. good story.

thajones

iTrader: (4)

EGR valve = knocking? I thought that was a "lifter" thing or something.

Time to play under the hood again...

Greeny

iTrader: (43)

Cleaning the egr valve may help some of you guys that have failed inspection or about to go get inspected...

Dillbag

iTrader: (4)

His EGR valve probably had carbon/crud build-up in it, causing it to stick open slightly. This lets exhaust back into the intake to go into the cylinders. That exhuast gas would displace some of the air/fuel mixture going into the cylinders. Since you can't re-burn already burnt gasses, you get a noticeable loss in power.

If an EGR valve is working right, you can apply vaccum directly to the valve, and it should open and either kill the engine at idle, or make it run REALLY rough.

Wanna back me up on this Wiking? Oh hell, just read my sig.

Wiking

You have got no backup needs, I bet u have more experience on EGR...

Tarzan: Can u describe more the knocking sound, behaviour. How many miles was needed before cleanup time?

Tarzan

Dillbag: the opposite. The EGR valve is there to let some exhaust gases back into the intake, in order to reduce O2 content in the incoming air and thus reduce temperature in the combustion chambers. If there is carbon buildup two scenarils possible: less exhaust gases coming in results in higher temp and easier knocking. Could have been the oppoiste - too much exhaust gases and failed emissions. My CO was always very low. I thinks...

Wiking: Say, I am driving on a slight upgrade at say 30-40 km/h and hit the gas. There will be 2-3 knocks from the engine and then she will accelerate lazily and drive lazily for the next 10-20 kms or until I shut it off. In hot weather there could be many more than 2-4 knocks.

Wiking

Only Drivin and hot engine? Asking cause nowadays my cold startup causes three knocks (like diesel) as engine revs alive. Everythin normal, but the noise is like pre ign or whatever... like ign too advanced for 2seconds. I have never touched the EGR (about 85k miles).

Btw. The two pneumatic valves are adjustable. No info anywhere? FSM has blk hole again here...

Tarzan

Yes, only after driving for half an hour - never before that.
I think the only way to set the regulator on the EGR valve is by the pressure in the hose. Realistically, the impact would be in the O2 content in exhaust gases, but I do not think that they (Nissan Plant) would plug a wideband O2 sensor just to tune up every new engine - it would be too time consuming and costly.

valz23

iTrader: (1)

In many states they don't test this part of emissions. At the DSM.org (the dsm site) a lot of people recomend just blocking the EGR valove off. You can even buy a block off plate for it. This is a very common mod with DSMs. I blocked mine off (just used the gusket off the valve itself as a template to make a block off plate out of thin metal) and drove like that for years. I passed emissions every time (I also had test pipe on it), and it actually gives a few extra horses. Ofcause, this is for "offroad" use only, since it is illigal.

Tarzan

You will pass emissions with no EGR valve, but if like me, you use 91 octane and advance your timing, you risk melting your plugs, valves and pistons.

valz23

iTrader: (1)

And if you fill up with 87, and advance your timing even farer, you'll you'll probably melt your crank as well. Driving without oil helps, too. A guy came to my friend's shop with a Corolla w/70K miles on it (he owned it since new) says his car just stoped running. I guess he kinda spaced out about checking (I'm not even talking about changing) oil. He said something like:"but it only has 70K miles on it", and when my friend asked him when was the last time he checked it, he said never. Somehow he did figure out that the car needs gas, though, since it died at a gas station.

Dillbag

iTrader: (4)

yeah, what you said is right as well tarzan, i just didn't mention it, but that is what the egr valve does. I just ment that i've seen them hang-up in the slightly open position due to a bunch of carbon in there, causing funky driveability issues like you described.

Tarzan

LOL, I've seen people like that Corolla owner... One of them tried to sell me his Audi 5000: his antifreeze looked like custard and oil resembled stuff they spray on the driveways.

Dillbag

iTrader: (4)

Oh yeah, seen it all, see sig.

andy044

iTrader: (5)

can i clean my egr valve, prep both gasket surfaces correctly
and then use RTV or silicone as a gasket?
or should i use the old one?
i just ordered a bunch of gasekets and i dont want to make another order

Wiking

Theres a general warnin that O2 sensor doesnt like silicone, so dont let horses a cahnce to eat it...

Tarzan

The EGR valve gasket is $5 at the dealer and it's made of smthn like asbestos.

valz23

iTrader: (1)

I don't know what that matterial is called, but it looks like metal with layers of thick foil on both sides. I just had my EGR off, as well as the most of the rest of the engine. This was a weekend from hell. I changed the VTC's, Knock sensor, etc., etc. I was truing to change the water pump as well, but thanks to the NAPA, I had to put the old one back on, thank God it looked like somebody has changed it before (looked great). First time they told me they had a brand new pump in stock for $36 (they cost about a $100 ea. brand new). I asked him twice if he was sure that it was the DOHC pupm, he promised. So, I rushed across the town to the store, he gives it to me, and what a surprise, it's an SOHC pump. He looked at me like I was an idiot for saying it, since his computer knows better. Then he ended up finding it in a book that I was right. He had to order one ($57 rebuilt, who cares that he said they had one for $36). I also ordered the both radiator houses from him. I come back to pick it up 2 days later, figured I'll give them an extra day, they got the pump, but forgot to order one of the houses. So, my project was officially off for that weekend. And what do you know, when I took my water pump off, they looked almost the same, exept for a couple of details, because off which, the only way I'd be able to put the new pump on, I'd have to either pull the engine out, or take off the lower timing chain. So, since it was Sunday night by then, I had to put the old one in. The most f**ked up thing was, when I went to return it yesterday, he listened to my complains, and then told me that he will have to deduct the cost of the guskets that came with the pump ($1.25), I threw them out, because they had gasket maker all over them.

95turbo gxe

iTrader: (25)

dam I dont understand but hey cool!