WK1 Troubleshooting / Problems Discussion / Dealer ServiceIf you are having some problems with your Jeep Grand Cherokee SRT8 and need assistance in troubleshooting and diagnosing the problem, this is the proper place to discuss it. Were you treated fairly or poorly at a dealer? Warranty issues? Let us know.
Valid point about the overlap but she's solid once it settles down. initially it bounces a bit. I am no expert man. Keep in mind when the jeep first fires up the RPM's bounce a bit (at least mine does) more RPM=more vacuum.
Last edited by Tim H Calgary; 11-30-2012 at 08:29 PM.
Thus you would figure this out by the way the needle moves then correct?
Mornin' Joe,
Actually, with the leakdown test if the intake valve leaks you can often hear air blowing into the intake manifold, exhaust valve leakage hear it in the tailpipe and if the piston rings leak you can hear it at the oil fill. A good initial indication of piston rings starting to leak would be an increased amount of oil in your catch can on a regular basis.
I mentioned the bearing wear because I don't how many miles you have on your engine. An indication of bearing wear would be a decrease in oil pressure. I see in your screen name "NY", I'm assuming that means New York. I bring this up because detonation can cause the engine bearings to be hammered when detonation causes the piston to try and travel down at the wrong time (this is why modern engine controls retard timing in an effort to compensate). Why did I bring detonation up? Well last month many gas stations in New Jersey that were substituting both 87 and 89 octane gas for premium and got caught and tried in court. Did you get gas in New Jersey and run you Jeep hard???
I know your not building a 8,000 hp supercharged engine and replacing the bearings every 1,000 feet.
Maybe you could ask some of the engine builders on this site what our bearings look like when they recieve core engines and disassemble them.
Just my 2 cents...
Guy
Last edited by SRT8-DOUGLAS SR; 12-01-2012 at 06:22 AM.
I appreciate ur input guy! I do live in westchester NY ad I have 27,000 miles on the jeep. Ill tell u what. I hear all kinds of weried shit comming from my engine from the inside(driver seat) and from the outside and hood open. But it may also be me. Lol. She seems to run ok but I am a lil nurotic with wanting her running tip top at all times. I do plan on doing a BIG SC build and will be doing a procharger sooner then later. Ill take all input and I also like to do these tests myself so I know and can somewhat diagnose an issue so the dealer can't BS me with any bullcrap repairs they say I need.
Another question is whas the best place to hook up the vacuum gauge to? The brake boost line or the line at the top of the mani right behind the TB where the catch an goes??
I used to visit large car auctions weekly, and a old guy showed be a very basic test to check engine condition. When the engine is warm pull the engine oil fill cap and place your hand on it. If you feel pressure it indicates excess crankcase pressure, the piston rings could be leaking or the PCV system is blocked (if you pull the PVC from it's source that takes the PCV out of the equation). If you feel vacuum the engine should be pretty healthy.
Still, hard to judge bearing wear.
Guy
Last edited by SRT8-DOUGLAS SR; 12-01-2012 at 07:18 AM.
The Following User Says Thank You to SRT8-DOUGLAS SR For This Useful Post:
well ran the test today and she sits pretty much at 15inhg when i slap throttle it she spikes down to 0 then to about 23 then back 15. if i hold it at a higher rpm she will sit around 23 untill i lay off then back to 15 again. seems about right? any objection? my engine should be running tip top i assume??!!
well ran the test today and she sits pretty much at 15inhg when i slap throttle it she spikes down to 0 then to about 23 then back 15. if i hold it at a higher rpm she will sit around 23 untill i lay off then back to 15 again. seems about right? any objection? my engine should be running tip top i assume??!!
OCD much? You ride is fine!!
You might drive yourself insane if you throw a SC on your Jeep. Just wait until you start slipping/throwing belts, TC starts making weird noises, trans starts slipping, boost fluctuates, etc.
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