rocker replacement observations

jeepdan · **Posted:** Thu Oct 03, 2013 3:56 pm

CRD #2 124,000 miles, first 100,000 miles of use and maintenance unknown.

I found all rocker rollers loose, only a few that were very wobbly.
I'm happy with that because the camshafts haven't been damaged, and didn't need replaced.
I had some concern with several of the exhaust valve stem tips as shown in the picture.
Makes me wonder how well the new rockers will mate to the old valve stems.

SOMETHING TO WATCH OUT FOR!!!
While pulling the cover off, one of dowl pins came out (rear pin) and was lying on the head.
Thankfully it didn't fall into the intake port without me knowing! :!:

I improved on the socket idea with soft aluminum wire wrapped around them so that they wouldn't fall into the intake ports and, also to allow my wife to remove them easily while I lifted the heavy cover up.

bugnout · **Posted:** Thu Oct 03, 2013 10:16 pm

Some of my valve stems looked similiar with 135,000 miles. I had them dressed by the machinist when I had the head tested.

How many lifters did you replace?

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

I bet you see a fuel economy increase with the new rockers. The valve stems should not cause any issues.

jeepdan · **Posted:** Fri Oct 04, 2013 8:28 am

GreenDieselEngineering wrote:

I bet you see a fuel economy increase with the new rockers. The valve stems should not cause any issues.

Thanks, Good to hear.
I'm hoping to have everything buttoned up before the ECO-Tune arrives.
After that, I know I will see an increase in economy. I average 27.5 mpg in CRD #1 :BANANA:

Hexus · **Posted:** Fri Oct 04, 2013 8:47 am

I have done entirely too much driving this week, but with new rockers/lifters and my GDE Tune and all the other work that I did, I'm consistently seeing 33MPG hand-calculated on the interstate and about 30mpg in town.

SFHLibertyCRD · **Posted:** Fri Oct 04, 2013 1:48 pm

Hexus wrote:

I have done entirely too much driving this week, but with new rockers/lifters and my GDE Tune and all the other work that I did, I'm consistently seeing 33MPG hand-calculated on the interstate and about 30mpg in town.

What were you seeing before? That is amazing.

EDIT, nevermind, saw you were getting 27.5 average previously. Man, that is the highest I ever got, and that was driving it across the country 99% highway driving around 70mph. I hope I can find ways to up that mileage a bit.

jeepdan · **Posted:** Wed Oct 09, 2013 1:20 pm

I just installed the GDE Eco-tune in CRD #2 and went for the first test drive after the glow plug/rocker replacement.
My heavens did the new rockers, intake gunk removal, and the GDE tune make a difference :BANANA:

Also, I had been hearing a light chirpy squeak for quite a while that I couldn't track down, it's gone

dieseldoesit · **Posted:** Wed Oct 09, 2013 1:39 pm

Hexus wrote:

I have done entirely too much driving this week, but with new rockers/lifters and my GDE Tune and all the other work that I did, I'm consistently seeing 33MPG hand-calculated on the interstate and about 30mpg in town.

What tires do you have on your Jeep?

joelukex4 · **Joined:** Thu Sep 29, 2011 4:54 pm **Posts:** 386

I feel like I am the only one whose mileage went down. I was getting 29 - 30 mpg early this summer and when I had the GDE ECO tune added in August my mileage went down to 27 - 28 mpg. I was hoping for an increase to above 30 mpg all the time. This is strictly interstate with cruise on at 73 - 75mph.

Hexus · **Posted:** Wed Oct 09, 2013 2:07 pm

joelukex4 wrote:

I feel like I am the only one whose mileage went down. I was getting 29 - 30 mpg early this summer and when I had the GDE ECO tune added in August my mileage went down to 27 - 28 mpg. I was hoping for an increase to above 30 mpg all the time. This is strictly interstate with cruise on at 73 - 75mph.

If you are depending on your EVIC cluster to calculate for you that is probably why you are seeing the disparity.

papaindigo · **Posted:** Wed Oct 09, 2013 2:31 pm

For what it's worth:
1. the speedo and odometer are required to be accurate to +-5% with OEM tires but can be off in either direction by a different amount never mind what happens with different size tires. The only way to be sure of the correction factor is to check by GPS (hint Interstate mile markers are IMHO not to be relied on). I favor 2-3 checks of the odometer on a minimum 25mile run on a reasonably straight flat road as I have no clue how a GPS factors in hills and curves vs actual pavement miles. Same for speedometer but for that you only need 1-2 miles at a constant speed (I'd suggest an indicate 6mph)
2. the EVIC gets it's numbers from who knows where and tends to be wildly optimistic from the factory. The original GDE tune made it more optimistic but for the last several years (say since the summer of 2009) the GDE tunes have reduced the inaccuracy to noticeably less than factory but still not terribly reliable. Translation Keith has done the best he can within the coding perimeters available to correct the EVIC. In that context if you have been relying on the EVIC, before/after GDE tune, for mpg it would not surprise me to see a drop in EVIC mpg due to the GDE tune reducing the optimistic inaccuracy. Compounding that are a host of factors that can impact actual mpg including speed which all things being equal carries a 10% mpg hit when you increase from 62-72mph unless of course you are running from Flagstaff, AZ to Tempe, AZ which is all downhill or something similar.

Pre-GDE typical hwy mpg for me at 62mph/1800rpm GPS corrected speedo/odometer was 27-an occasional 29mpg; post-GDE same vehicle same conditions same road 31-33mpg. Oddly my son, stoutdog, drives an 06 and can do a bit better post-GDE under the same conditions, etc. although he is running Kap's tstat mod with a 195f tstat and I have factory.

joelukex4 · **Joined:** Thu Sep 29, 2011 4:54 pm **Posts:** 386

Hexus wrote:

joelukex4 wrote:

I feel like I am the only one whose mileage went down. I was getting 29 - 30 mpg early this summer and when I had the GDE ECO tune added in August my mileage went down to 27 - 28 mpg. I was hoping for an increase to above 30 mpg all the time. This is strictly interstate with cruise on at 73 - 75mph.

If you are depending on your EVIC cluster to calculate for you that is probably why you are seeing the disparity.

All hand calculated, which is the only way to do it. Interestingly the pre-GDE EVIC would be about 32mpg and hand calculated would be around 30mpg. Post ECO tune EVIC is 34 - 36mpg and hand calculated is about 28mpg. The disparity increased.

joelukex4 · **Joined:** Thu Sep 29, 2011 4:54 pm **Posts:** 386

[quote="papaindigo"]For what it's worth:
1. the speedo and odometer are required to be accurate to +-5% with OEM tires but can be off in either direction by a different amount never mind what happens with different size tires. The only way to be sure of the correction factor is to check by GPS (hint Interstate mile markers are IMHO not to be relied on). I favor 2-3 checks of the odometer on a minimum 25mile run on a reasonably straight flat road as I have no clue how a GPS factors in hills and curves vs actual pavement miles. Same for speedometer but for that you only need 1-2 miles at a constant speed (I'd suggest an indicate 6mph)
2. the EVIC gets it's numbers from who knows where and tends to be wildly optimistic from the factory. The original GDE tune made it more optimistic but for the last several years (say since the summer of 2009) the GDE tunes have reduced the inaccuracy to noticeably less than factory but still not terribly reliable. Translation Keith has done the best he can within the coding perimeters available to correct the EVIC. In that context if you have been relying on the EVIC, before/after GDE tune, for mpg it would not surprise me to see a drop in EVIC mpg due to the GDE tune reducing the optimistic inaccuracy. Compounding that are a host of factors that can impact actual mpg including speed which all things being equal carries a 10% mpg hit when you increase from 62-72mph unless of course you are running from Flagstaff, AZ to Tempe, AZ which is all downhill or something similar.

Same tires, same roads and multiple trips which should eliminate weather conditions; wind, temperature, etc from the equation. We are talking about 1-2 months apart so I don't believe condition of the vehicle has changed enough to be a factor.

Hexus · **Posted:** Wed Oct 09, 2013 7:14 pm

I'm going to go ahead and attribute it to rocker wear and soot buildup then.

New rockers, Cleaned intake, GDE Tune, New Turbo = 34 MPG consistently at 70-75mph and 28mpg with any other normal driving if I'm not torquing around constantly.

That is through 4 oil changes now at 1k, 6k, 6k, 6k, so 19k miles of hand calculated averages.

rocker replacement observations

Who is online