Repair Questions

[CareyWeber]

Well I now have 207K miles on my 97 K3500 CC SRW 4x4 truck and the water pump has started leaking and while checking the water pump out, it looks like I have a head gasket leaking on the front of the drivers side. I am trying to decide what all to replace and the order to do it in. All the cooling system hoses, block heater and the radiator have about 50K miles on them (I think I'd replace the lower hose just the same to I don't ever want to that one on the side of the road.) The truck does not use more than one quart of oil in a 2500 to 3K mile oil change (pulling will likely up that some).


Replace water pump, timing chain (no gears for a +207K mile engine), damper, crank pulley, vacuum pump, crossover pipe, injectors, clean the radiator and coolers too, check/replace any bad glowplugs, port match the heads/manifolds and head gaskets.

Replace head gaskets, crossover pipe, injectors, check/replace any bad glowplugs, port match the heads/manifolds and head gaskets. Drive a day or two flush the cooling system (keeps from running any dirt/crud through the new water pump) then do the rest.
Should I have a valve job do on the heads or will that just cause oil to get pushed by the ring due to the increased compression?

My first thought is to do everything at one time what do you guys think?

I'll bet the AC system will require work after al that is done too.

How many more miles will do you think I'll get before needing to do a full rebuild?

Would you do it in the truck or pull it (If I pull it I doubt I'd stop at the above list and I anit roll'n in the $$ if ya know what I mean)?

ps I'm happy getting +200K out of the water pump and the head gaskets too.

Carey

[tommac95]

comments, if not answers....

>How many more miles will do you think I'll get before needing to do a full rebuild?

Seems to vary widely. The limiters are block-mainweb-cracks and hydrolocking from leaking headgaskets into cyls. Most likely your heads are all cracked up.

I'd begin by checking for block cracks. If that's OK, i think i'd plan to install new heads [Pen En ca$1000] BUT you'll probably want to resurface the block firedeck , because the steel-seal-ring in the headgasket(s) has made a depression in the block that will compromise new gasket sealing. This resurfacing is not effeciently done while block in truck. Good results have been derived from remanned heads.

If the block webs are cracked , you MAY ignore , but might look for a new block before proceding. That should be start-point for decision-making tree....

My cylinder wear seemed to be 6 cyls worn .002", two cyls worn .007". (175kMi) The block/ring technology appears designed for wear-resistance/endurance. Given your maintenance, i'd be optimistic , but start with block crack survey. If block cracked maybe just do waterpump and headgaskets, run while locate nice donor block!

If you sand down the firedeck (with a nice straightedge) you'll get a good bit of abrasive particles in the block waterjacket. So you'll want to rinse that out somehow.

I think my heads had been 'port-matched' by previous TDP owner. The valve seats were cracked, and there was little margin for the new head sealing surfaces to meet the ExMan flanges; gaskets wouldn't work, but it did seal after carbon bridged the gaps.

Do consider new engine mounts at this interval...J.KDies had some nice shots of worn/collapsed ones. Billman reported slumped mts contribute to oil line abrasion/leaks; vibes also can develop.

good luck.

[gvig]

Carey,

I understand your trepidation when considering changing to Phazer gears in a high mile engine, however.... I just did that on my 95. The gears make it run like a new engine. I wish I had done it a long time ago. The difference is dramatic. With the cost of fuel it won't take long to save back the cost involved. My in town mileage just went from 11.5 to over 15 with no other changes.:D Can't wait to do some highway driving to check the difference.

And if I change engines I will remove the gears and use them again on the replacement. I'm too cheap to let them go.

George

[Robyn]

Hello
Well now, at 200K+ I would go about it this way.
1- The engine is going to be dirty, Pull the little beast out and get it on an engine stand and power wash it.

2- The heads need to come off as does the pan and while you are it pull the front cover too as you will have the water pump off at this point.

3- check the block deck for flatness and clean it real well. Be sure you dont have any bad errosion around the fire rings of the head gaskets.

4- The heads are going to be junk at this stage of the game so plan on a set of new heads from Clear water. These are new castings from Newzealand and reconditioned valves and used springs and shims with new keepers.

5- Check the timing chain and gears, a new chain may do the trick oif the sprockets are good. ( Mine were at 247K)

6- check the bearings and most likely you will want to drop in a set of new shells. ALSO LOOK AT THE CENTER MAIN WEBS FOR SIGNS OF CRACKS

7- If the cylinders are looking ok you may not wish to pull the pistons.
refit a new rear main seal as well as a front cover seal and gaskets.
clean and refit the pan. Drop on the new heads.

8- Install a new set of (16) rocker arm guide buttons ( the little plastic thing in the rocker arm shaft that guides tha rocker).
These little beasties can break and when they do it can spell doooooooooom to your little diesel rat motor.

9- replace your water pump and a new T stat is in order too.
Paint to suit and drop back in the truck and go again.

Good luck
Robyn

[gmctd]

At 444kmi, George, you would have seen the same improvement with a new chainset- same at 100kmi, or 200kmi, etc

Folks do not realize that, because noone at that point would be willing to install the other set for comparison.

The improvement results from restoring correct camshaft\crankshaft timing - PCM corrects for retarded timing as mechanical wear increases, to a point.
DB2 would require mechanical adjustment to maintain 'correct' timing

The main benefit of the gearset is that cam\crank timing never degrades, with regular engine oil service intervals.

[gvig]

gmctd,

Good point, however there is that other factor involved too. DSG grinds the reluctor wheel with a 4 degree advance, which the new chain would not have had. That tricks the computer into using what is otherwise stock configuration and yet it is advanced from what a chain would have provided.

Anyway, I am greatly pleased.:)

It starts without using throttle, idles smoothly solid as a rock, and runs like it never has since I got the truck.

I'm a happy camper.:p

[gmctd]

I'm fairly certain the +2deg timing advantage is due to reduced backlash gained by using the gearset - even a new chainset will have not less than 2deg slack, or installation would be exceeding difficult.

Some new chainsets have more than 2deg slack, depending on the oem.

The obvious offset between the camgear teeth and the crank gear teeth is because of the pitch diameter of the two idler gears - the keyway in the camshaft gear is offset-corrected, so the timing marks line up at TDC even tho the teeth do not.

The tooth mis-match, therefore, does not indicate advance, but in fact appears to result in a retarded condition - the camgear tooth adjacent the timing mark is still approaching TDC when the crankgear is at TDC.

One of the Mods here, and I, searched seperately, but could not find any info that the gearset has a built-in +4deg advance.

Other than the mis-drawn timing cartoon - that crank gear has 16 teeth, where the real gear has 24 teeth @ 15deg each - the included instructions with the gearset do not mention any timing advance.

I compared the oem and DSG reluctors, and the keyways lined up, aIr.

I'm running the gearset, also, installed shortly after installing a new chainset, so the pros and cons of each are fairly clear to me - I prefer the gearset, but my plans involved keeping the truck, and doing some hi-perf investigations.

No pros or cons, here - a new chainset will restore oem driveability, as will the gearset.

So, with utility being a consideration, let the wallet be the guide - a new chainset will not do the engine any disservice, nor will the gearset turn the truck into a screamin' 12-sec street monster.

A Tech-II would be required to notice any difference in performance between the two.

That's my story, and I'm stickin' to it.....................

yrmv

[gvig]

Having read the pro's and con's of the gearset here on the bulletin board, I did a strict comparison of the factory reluctor wheel and the DSG reluctor wheel before installing. With the bores strictly aligned, and the keyways also accurately aligned, there was about a .110 offset of the "cogs" on the OD of the reluctor wheel.

I could have gotten out the comparison tools and cleaned off the granite block. I didn't feel the need. All I was concerned about was, "is the CPS getting the signal of TDC earlier or not?" There is no doubt it is getting it earlier but what that means to the overall installation I will leave for smarter than I to ascertain.

Certainly do not want to start a disagreement over the minor differences, and you are right in that a new chain would have restored "like new" driveability." I wanted more, and that it runs so well now is very satisfying to me.:)

George

[gvig]

And one other thing of note, having owned and driven a 12 second street monster, I can assure you, my truck is not.:(

However, it will start within 12 seconds, does that count?:D

George

[gmctd]

No intent to do battle, George - just wanted anyone to know the gearset is not magic, and that the chainset is functional in restoring power.

Have been a few over the years who've complained that the extra cost did not return the 'promised' power gains, same as with the price of a charge-air cooler on a 1500 suv never used for towing\hauling.

If one is content with the results and the state of the wallet, then more power to us, eh?

[Warren96]

My truck is a ''keeper'',that is why a gear was chosen over a chain.It may have cost more than a chain, but it is also the last time i will have to deal with it! I have almost 200K on it now and another 200K seems posible.