Inspecting and Replacing PD TDI camshaft
This How-to covers the inspection and replacement of the camshaft on Volkswagen 4 cylinder PD TDI's from 2004-2006. This will cover the BEW engine in MK4 as well as BRM in MK5 sedans.
I'm going to split this How-To into 2 sections, the symptoms, causes and Inspection of the camshaft and then the actual replacement of the camshaft. Replacing the cam requires removing (hopefully replacing) the timing belt and components which aren't included in this How-to (should follow shortly). Youtube link at the bottom if preferred.
Causes/Symptoms/Inspection
-There's a few possible causes to the lobe wear on the PD TDI engines. First off many people believe the cams were just too soft, many aftermarket manufacturers offer Billet cams that should prolong the life. Another reason is poor oil, these engines require 5W40 oil rated to VW 505.01 spec. Lastly aftermarket performance companies claim the lobe profile is very poor and meant for a solid lifter whereas these engines used hydraulic lifters.
-Usually the exhaust lobes wear out first, taking out the lifter as well. When this happens the exhaust can't escape on the exhaust stroke and gets forced into the intake on the intake stroke. This results in a very obvious "thumping" in the intake. Once bad enough it can result in under boosting from lack of exhaust flow, poor mileage and miss-fire.
-Inspection can be tricky to the untrained/unexperienced eye. Exhaust lobes will wear first (starting at timing belt 1E,1I, 2E, 2I, 3I,3E,4I,4E). The lobes have chamfered edges, if the lobe edge is sharp then the cams wore out and the lifter will be as well.
In engine
On bench
Wore though lifter
Replacement
If you decided its time to do the cam up next is the replacement
Tools:
Deep triple square, torx and allen set
Metric socket set
Parts required:
Camshaft of your choice (Colt cams makes a quality upgraded cam that'll outlast the car)
Ina nitride followers
Cam bearings (I'm a fan of kolbenschmidt)
Cam Cap and injector rocker stretch bolts
Can also use non-stretch as they are significantly cheaper (Step 8)
Cam cap: Grade 12.9 allen M6x55 1.00 thread pitch
Injector rocker: Grade 12.9 allen M8X90 1.25 thread pitch
Tandem pump gasket
Camshaft gasket
Assembly lube (Federal mogul Sealed power)
Step 1:
Remove the timing belt with cylinder 1 at TDC and remove the valve cover. The rear bolts for the valve cover can be a bit tricky to reach down to with the intake installed, this is where the deep torx bits come in handy.
With the valve cover off you can remove the injector rocker assembly.
Step 2:
I didn't get a good picture of the tandem pump removal but it has to come off next. There will be 2 Torx bolts up top parallel with the valve cover mating surface and 2 smaller bolts down near the bottom
Step 3:
Time to remove the cam caps, cam and lifters. Remove the cam caps evenly as there will be upwards force from the lifters, once caps are removed pull the cam out and bottom bearings. The lifters then can come out, they can be suctioned in a bit so pliers will help.
Step 4:
With all the wore out parts removed compare them to your new ones to ensure they match up
Step 5:
Check the injector rocker assembly oil gallery plugs, 50% of the time for me atleast they're loose or missing. If they're loose or missing you're now loosing pressurized oil in the head accelerating cam/bearing/follower wear of your nice new parts. If they're loose peen the rocker assembly with a center punch to swell up around the plug. If they're missing your cam cap bolts that you removed in step 3 will fit in there snug and can get peened to ensure they don't fall out.
Step 6:
Re-assembly time, install cam bearings in the head and in the cam caps, give them a good coating of assembly lube. The cam caps only go in one place so check the number stamped in them (2 and 4 are the only ones that can get mixed up).
Step 7:
Lifters can get set in with a good coating of assembly lube then the cam. Ensure on cylinder 1 the exhaust lobe is facing up and forward and the intake lobe is facing up and rearward so that its at TDC compression stroke. Snug the cam caps down evenly to not put un-needed stress on the cam.
Step 8:
Cam cap torque procedure
Non-tty grade 12.9 bolts get torqued to 12 Ft/lbs, when torqueing tap the cam caps with a mallet to make sure they're sitting square.
OEM stretch bolts 6 Ft/lbs + 1/4 turn.
If using non-tty you loose the shoulder of the bolt to ensure the cap is sitting square so this requires a bit of common sense.
Step 9:
Injector rocker assembly torque procedure
Non-tty grade 12.9 bolts get torqued to 25 Ft/lbs with the outside ones on cylinder 1 and 4 to 23 Ft/lbs to prevent cap distortion
OEM stretch bolts 15 Ft/lbs + 1/4 turn
Step 10:
Re-install the tandem pump with new seal and install the timing belt
Step 11:
With a new cam its best to check injector lash. If not checked and out of adjustment the injector could be bottomed out during run in and damage the injector, rocker assembly, cam and head.
VW procedure requires using a dial indicator to make sure injector is fully depressed but that can be tricky as everythings aluminum. Simplified version is set the intake lobe facing upwards at the rocker assembly roller, that ensures the injector is fully depressed. (check out the inspection section for lobe numbering)
Step 12:
Loosen the jamb nut, turn the set screw in until resistance is felt (injector bottomed out). Then loosen the bolt 1/2 turn and tighten the jamb nut. Do all injectors then your good to finish re-assembly.