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Alfa Romeo 164
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Discussion Starter #1
Having success with my HVAC repairs, next job on my list was to check the timing belt.
Last replacement was at 90000km when i purchased vehicle. Current mileage is 140000km, age of belt 15 years old.
I was expecting to see dry rot on the belt, cracking at tooth profiles, not to bad, has weathered well. Down side was finding a hole in the belt.
A Real bonus with these COP 24 valve motors in no need to remove the crankshaft pulley.
Block casting and design give you ample room to slip the belt out from behind the crankshaft pulley.. Once the crank position sensor is removed, you have plenty of room. Trick is being gentle.

Well, no option, change it.

Alot of gravel was on my subframe, (in NZ gravel is widely spread on mountain roads in Winter where black ice occurs.)
I fear one may have flicked up, these 24V timing belt covers leave tensioner side pretty exposed.
So after disassembly, I checked the auto tensioner.
CHECK AND RESET TENSIONER
Nice and dry around the top, no sign of wetness at top seal and shaft.
Placing in a press, slowly pump shaft back in, nice resistance should be felt. Release and watch shaft release out fully, then slowly and gently pump back in. Then place pin (strong cotter/split pin works) through housing and shaft ready now ready for fitment.
Store this item upright (use a coffee mug) Laying flat, or upside down can cause an air pocket inside tesioner, creating sponge state when installed.
IDLER AND TENSIONER BEARINGS.
Okay, bit of weather has setteld on the bearings, free spinning them, they sound a little dry, this is no problem.
Being on the tools 30 + years, my judgement to re use was put into motion.
I removed bearings from block, then rolled them with load on a flat workbench. No notchiness felt, smooth rotation only, indicating balls not worn, only dry.
Clean around bearing dust/grease seal. With careful procedure, using a small pick, insert into lip of seal. Gently lift and using Wurth HS 2000 spray grease, squirt into bearing. Then also lay flat, flood bearing and allow to draw in by turning bearing.
To get rid of minor surface rust on bearings, i used WD40 on 800 wet n dry.
With bearings bolted in place, when spun, no noise evident.

Both tensioner and bearings serviceable for next belt duration.

Fitting the belt.

Fit the new belt on crank first, then with no slack on your belt,over idler bearing, then feed onto exhaust cam LH head, then Inlet cam LH head, then under idler bearing, then RH head inlet cam, Then Rh head ex cam. ( Camshaft pulleys should be loosend and turn on camshaft taper. Tighten when new belt fitted, Torque to spec at final assembly.)
Then over o/p drive, then tensioner bearing.
When you release the auto tensioner, check the protrusion of shaft, should be aprrox 3-4 mm at final assembly after rotations. Adjustment for this at t/belt tensioner bearing, bolted to bearing support. (loosen bearing to allow movement either direction to increase or decrease protrusion)
Remove your cam timing tools, rotate engine several times and refit cam tools, Crankshaft pulley TDC mark should line up with mark on block housing. Check tensioner protrusion. Adjust if not enough or to much protrusion.

Reassemble and run with confidence.
 

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You dodged a bullet with the stone damage!

I intend to do 100k kms on my belts. Replaced a year before I got the car at 105 k ... now ~170k.
Pete
 

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Alfa Romeo 164
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Discussion Starter #3
Cheers brother, see you are up in the North Island. Yes, very lucky indeed, may i add, in 30+ years of being a mechanic this is the second time i have come across this. First time was on a Ford Escort ex WRC car, owned by Brian Green over in Palmeston North. I did his belt one week before the Ashley Forest Rally Sprint, many years back.
 

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What year is your 24V 164?
 

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Del, It appears in the photos to have the aux gear for the oil pump

Pete
 

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Yes, it does look similar to ours, with the 90 deg rear cam/belt engagement. And he runs the belt how long? Certainly doesn't worry about the belt age. I notice that Dayco, perhaps the maker of the best belt, recommends changing the belt at 50k miles.
 

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Alfa Romeo 164
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Discussion Starter #7
Hi, year is 1994, yes i worry about belt age, that's why i checked it. Belt was within recommended mileage interval, (done 50000 km / 30000 miles) but well over recommended age interval. Storage has helped preserve the belt from dry rot, was in a warehouse on wooden floors, no damp. Whenever i returned to use the car and took from storage, inspection of the belt was carried out. A good torch, and a good stick mirror are handy for this, and knowing where to look. Vehicle sat outside for one winter, rising damp causing deterioration in engine bay, this is why i have tidied up the engine. Next job is to restore the air cleaner box.
 

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