Engine Performance Question - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 06-18-2012, 08:22 PM   #1
Newb
 
Join Date: Apr 2012
Posts: 8
Engine Performance Question

So I've been plugging away trying to figure out what is going on with this engine. (1998 Wrangler SE with a 2.5L) It's been running like crap and doing a ticking/knock during idle it's also really sluggish while acceleration, feels like a misfire; reminds me of times I've gotten water in my fuel. Had the codes ran, its throwing a misfire on #1 P0301& a CAT code p0420. I did a compression test and it was surprisingly all within specs; #1 one was a little low but still within a 15% difference. (#1) 140 (#2) 150 (#3) 150 (#4) 155-160. I also did a leak down test; #1 was 9-10% the rest were 5%-8%. I also noted that during the leak down, cylinder #1 made the radiator fluid rise and over flow. I changed the head gasket not too long ago. (unfortunately I didn't check the mating surface for flatness)

I guess my question is, would a warped head give these type of readings and make the engine perform in this manner? Would this also make cylinder 1 knock or is that something else?

TeeJayPee is offline   Quote Quick Reply
Old 06-18-2012, 08:36 PM   #2
Jeeper
 
Rubicon2's Avatar
 
Join Date: Nov 2010
Location: Northern Lower Michigan
Posts: 1,360
Yes on all accounts. If cylinder 1 is as you say it is and you noticeably saw coolant rise and fall during the test I would say you have a gasket leak or a warped head. The cause of your bad O2 sensor is most likely caused by coolant contamination in the exhaust. Has your coolant level dropped or have you had to add coolant since you replaced the gasket? You can buy a block tester at any auto parts store to verify further that it is leaking. A block tester is used to check for combustion gases in the cooling system. You fill the block tester with a small amount of special fluid that changes color if it detects combustion gases in the coolant. Just be sure follow the directions for it to a T. Coolant also destroys the Babbitt on crank bearings and could be the cause of your knock. I would change the oil and inspect it for coolant as well.

__________________
DO OR DO NOT... THERE IS NO TRY.
Rubicon2 is offline   Quote Quick Reply
Old 06-18-2012, 08:48 PM   #3
Jeeper
 
div4gold's Avatar
 
Join Date: Feb 2012
Location: WA
Posts: 506
I was just going to say pretty much what Rubicon2 just posted. I'd bet , because of the leak down test, Nr1 either has a gasket leak or a cracked head/warped head.
__________________
2006 TJ Unlimited, stock.
div4gold is offline   Quote Quick Reply
Old 09-20-2012, 07:57 AM   #4
Jeeper
 
Join Date: Jul 2010
Location: Mooresville,NC
Posts: 190
Cracked head maybe.
Got 4 Lo is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 03:24 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC