Im just tearing into my liberty it has 175k miles on it. I have done injector canceling with my scanner and its #1 cylinder, it still has some output but the noise changes when cancelled. Im hoping its rockers but because its loosing compression out the intake im concerned. If its a valve can the pistons be remove with the engine in the vehicle and with this milage what is the best route to go. Jeep is rust free and in overall great condition!

ok I have the cams off, it was a blown apart lifter, also most of the rockers are bad, intake cam is toast, After seeing post about valves breaking I'm not sure how far to go, with 175k miles should I pull the head and replace valves? I would like to run it another 100k seeing that the body/frame is rust free and and I love the ecomony

I would. It's not that much more work to pull the head, and you'll get a look at the piton tops, and sleeves to see what condition they are in. The engine has to be removed to tear it apart any more.

Mike

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2005 Liberty CRD Limited
DIY Garage Remanufactured Engine with GDE Full Torque Eco Tune from mile zero.
ARP Studs
Cummins Lift Pump
Transgo HD2 Reprogramming Kit
DIY Rebuilt Tranny Pump
Suncoast Torque Converter
2nd Generation Fuel Head
Sears P1 Battery
Hot Diesel Solutions Thermostat

Pull the head and have it checked for cracks.
Replace the exhaust valves.
Install ARP studs.

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U.S. Army Retired

What he said. You are right at the tipping point in the range for a valve failure, and having lifter failures already means the system was stressed.

Get those valves out of there and put in fresh. That will set you up for at least another 150k.

Finally got back to work on the jeep, took the head off and glad to see the pistons and valves in tact. I took the head to my local machine shop to have it cleaned and checked out and put in my order to IDparts I ordered the graf water pump hopefully they hold up well? Also I'm just curious about the high pressure fuel pump and timing, I did line up all my timing marks but I can't help but guess that it is a constant pressure pump and is not really timed with the engine but I haven't found any info on it that way?

No need to time the fuel pump.

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06 Liberty CRD--cheap lift and a Magniflow
04 Expedition--5.4L 4x4 Eddie Bauer
90 Bronco--5.0L another Eddie Bauer
81 Austin Mini--automatic, 1 liter of raw power
69 Cougar--398" of pure torque, when it ran

So you were the one who bought the last set of valves!
They are backordered at the moment, should hopefully be arriving next week sometime.

I always time the fuel pump. The notch on the pulley matches with the bump on the inner timing cover around the 8 o'clock position.

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Over 125 CRDs currently driving with my timing belt, rockers, or ARP Studs.
Bad noises = REALLY bad things.

Does that require lapping/grinding the new valves to seat properly?

Yes

_________________
U.S. Army Retired

How would you go about doing that, and why exactly? The new valves should be built to the same specification. I sure don't want to do all that work twice if there is something that needs to be done the first time.

The guys at Manley said that the valve seats only need to be lapped if they are damaged / rusty. For an in-service engine that shouldn't be an issue.

Edit: Here is a comment from another forum about this, and I am inclined to agree:

"But, you are totally correct that modern valve and seat grinding practices have nearly eliminated the need to lap valves. Part of the point that I am trying to make with the original poster is that lapping a worn valve and seat is no way to renew it. Lapping is a process to be used ONLY after grinding. To finish it off."

We shouldn't need to grind the seats on these at all. To check on this theory, I will take one of the cylinder heads that I have to a machine shop on Monday with the valves that I just got today, and have them inspected as if they would be installed in that head (it is wrecked so nothing will actually be installed) and see what the shop says.

Why wouldnt you lap the valves?
Especially when putting a new valve against an old seat?
Its not a difficult process and you dont need a machine shop to do it.
All you are doing is making sure that the valve makes a water tight seal against the seat.
http://www.restore-an-old-car.com/how-to-lap-valves.html

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U.S. Army Retired

Take it from an old mechanic that has done hundreds of valve jobs on heads with many of them getting new exhaust valves. They need to be lapped in to insure absolutely no leakage between the valve and valve seat! Ever heard of a burnt valve; that is what happens if the valve leaks by between the valve and valve seat during the ignition process, happens on gassers and diesels alike. When I first worked at a machine shop many years ago, we always performed a valve to seat fit and seal test when grinding valves and valve seats or installing new valves AFTER lapping valves and installing the valve springs by poring mineral spirits into the intake and exhaust cavities in the head and observe for ANY liquid leakage past the valve. It ANY leakage was observed, we would pull it back apart and LAP the valves some more against the seat to get a 100% perfect seal....

Anyone that would install reground or new valves against used valve seats without lapping them in to insure a perfect seal is taking a very huge and unnecessary gamble...

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Supporting Vendor and Moderator of LOST
05 Jeep Liberty CRD Limited
Ironman Springs/Bilstein/Shocks
Yeti StgIV Hot Tune
Week's BatteryTray
No FCV/EGR
Samcos/ProVent
SunCoast/Transgo
Carter Intank-pmp
2mic.Sec.Fuel Filter
Flowmaster/NO CAT
V6Airbox/noVH
GM11 Bld.fan/HDClutch
IronrockArms/wwdieselMount
98 Dodge Cummins 24 Valve

An update on the head rebuild, everything went together fine although I had two of the larger bolts left over from the inner timing belt cover, I looked for an hour and could not find where they went! Back to the repair this was the second time I had the front apart, first time for the timing belt and now. This site has been a great help with that, the only thing different I did both times is leave the radiator and front of the jeep in tact, I just take out the air box for the needed space and use an air chisel to loosen the clutch fan and bring out the shroud and fan together, there is plenty of room to work on the front of the engine.
When I drove the jeep home after the purchase (used 80,000 miles). It got about 27mgp, after egr delete and the tune it got 30mpg highway miles. Now after this repair it gets 33+mpg. The intake and head air passages were caked with over an 1/8" of slimy tar like goo. The effects of 100,000 miles of egr build up. It took several hours of cleaning to remove it all. My local machine shop cleaned the head and milled off .003 to square it up then took the same amount off the valve seats to maintain clearance and assure proper sealing of the new valves(the exhaust seats needed it bad). I can only assume that the diesel can now breathe better than ever and with out egr smothering it can maintain peak efficiency.