i have heard that cylinder numbers 4, and 6 are most likely to go out. is this because they run leanest? i will be installing 2 egts on my car and would like to know which cylinders i should attach the probes to. thx for any help

 

I have heard these were the cylinders that went bad in some of the ATI cars as well. It could be that they recieve slightly more air as it comes in through the throttlebody....they are almost straight across. It could also be that the coolant temp has risen more by the time it reaches the back side of the motor for some reason. Maybe it is a combination of just these 2 or maybe more factors.

 

the cylinder that pops is the lean one..LOL.......

 

 

Never heard of losing #4. I know #5 & #6 have both been lost with the majority being #6

 

so should i install the egt on the primary tubes for 5 and 6 or on the main collectors?

 

I think as long as you run timing control the egt's on the collectors will be fine. Why not save the money for the 2 egt's and get a wideband o2 like the fjo, techedge, etc.

 

i understand where your coming from but im going 2 b/c i already had them lying around and dont feel like selling em. 2 defi d egts. and since im gonna be using long tube xerds will it still be ok to mount in the collectors?

 

Mounting on a long tube header collector is way too far away from the engine. For maximum accuracy you should mount it on the leanest running cylinders as close to the head as possible.

 

cool thx alot guys im gonna mount them on the 5, and 6 like 2-3" from the head then.

btw is $60 a good deal to get the 2 bungs welded in for the egts?

 

yes, it is a good price.

 

I dunno the answer to your question but I do know that my compression numbers in cylinders 5 and 6 are both higher than the rest of the cylinders. Heres my compression for all the cylinders-

Cylinder 1- 185
Cylinder 2- 180
Cylinder 3- 185
Cylinder 4- 180
Cylinder 5- 200
Cylinder 6- 200

I don't know why they vary so much between cylinders.

 

Poor ring seating during break-in period or bad valve job.

 

TAKE PICTURES! please...

 

185 is spot on where it should be. You'll always get variation between cylinders however Nissan lists that you shouldn't have more than 14psi difference which you do. You only have that though as those two cylinders are well above standard so I'm not sure if it's acceptable or not. What did the dealer say?

 

Well, I initially had the car towed to the dealership after hydrolocking my engine in a rainstorm. They proceeded to get the water out of the cylinders. Afterwards they performed a compression test and the numbers I posted above are what they found. They said the numbers were okay, but I still think the water did some damage that the dealer did not notice. After all, they didn't even open up the darn block. Everyone I've talked to said my compression shouldn't vary that much. Also I've read about a bmw being hydrolocked, dealer diagnosing it as okay, then 20K miles later the engine was gone. It happened to be a piston a millimeter or two off spec. Oh well.

 

Thing is a large variation is bad but usually that's because one or more cylinders are far too low. In your case your getting a variation because a couple are high. I would tend to think that's OK.

If the dealer fixed it and said it was fine just hold on to the work order and if you have a problem later on it'll be fixed under warranty anyway.

 

Cylinders 5 and 6 tend to run leanest.
Probes generally should be between 4 and 8 inches from head, but check installation instructions on the instrument you are using.
$60 for two bungs is good price.
Best protection is to run some type of ignition retard/knock control device, because once the egt starts to soar it is a consequence of pre-ignition, so you are already potentially doing damage. And that assumes that under WOT you are actually going to visually notice it on the gauge/meter. Any warning chime is likely to not be heard under WOT anyway. Even flashing lights are not the best because you probably have your focus out the windscreen and on the road. Something like the J&S Ultra Safeguard unit will control by cylinder the timing, retarding it by 10 degrees, (20 if you want to set it that way). It reacts immediately, long before you could process the meter info, and lift your foot off the pedal. Just something to consider looking into.

 

If I had two I would put them in the collectors on both sides to measure the whole banks, that would be very accurate and a sweet setup. I only have one and it is on the driver side in the RT Cat pipe just after the header but before the CAT right where they meet sort of and has proven to be very accurate. When I had my leak down test on my blown engine the good cylinders were exactly 185 not more or less.

 

If the dealer fixed it and said it was fine just hold on to the work order and if you have a problem later on it'll be fixed under warranty anyway. [/B][/QUOTE]


Not with a Injen CAI that has hydrolocked