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Discussion Starter #1
Hi,

Now that is has happened for the second time, 10 years apart, am able to offer this conclusion with some degree of confidence: put the 'wrong' spec oil filter in your 24v 164 and expect a cambelt jump shortly after.
The first time this happened was in 2008, the morning after an oil change. The second time it happened was today, about 30 miles after an oil change and on my way to purchase a new oil filter as, guess what, the oil pressure was reading almost 2-bar higher than usual, hot and cold.
In all cases the oil used was exactly the same: magnatec 10w/40 semi-synthetic. Can't remember which oil filter was used the first time but this time it was one from Halfords for an Alaf 166 3.2 24v. 166 uses the same block and this filter was also listed as compatible for both the 3.0 24v GTV and 164. Carefully checked the tech specs and even the 1.5bar pressure relief setting was same for both this and purely 164 24v 3.0 listed oil filters.
Assumed it to be just a newer version, with a one or two vs two or one (can't remember which way round) internal drains. Thought the almost 2-bar increase was not a good long term idea, given the cambelt drives the oil pump, so was on my way to pic up another filter when it jumped. Limped car home to avoid further jumps and going to open it up tomorrow to see how many teeth it has jumped; guess two, maybe three on rear bank.
If my theory is correct, it could explain why 3.2 GT engines are designated a cambelt change every 36,000 rather than the 164's 72,000. By the way, my cambelt was changed last year, car covering less than 5,000 miles since.

What do you think?
 

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"change every 36,000 rather than the 164's 72,000"

No way. Almost all of us in the US change the 164 12V and 24V belts every 30-40k miles. I think the original spec was ~50k miles? And, if you changed it only 5k miles ago, I'm not sure why the belt changing interval would make a difference, thus I think that in your case the belt change interval is not the problem.

Did you use the oil you thought you had, not gear lube by any chance? No reason just changing the old oil with the same new oil should cause such a change in reading, esp since you hadn't changed the filter yet. I think this eliminates a filter problem, since the old filter seemed fine, with proper readings? A problem with the pressure sender or gauge? Haven't heard of a filter causing such a problem, esp with a medium weight lube such as 10W-40 oil.

Maybe a problem with the tensioner adjustment?

Keep us posted.
 

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Discussion Starter #3
"change every 36,000 rather than the 164's 72,000"

No way. Almost all of us in the US change the 164 12V and 24V belts every 30-40k miles. I think the original spec was ~50k miles? And, if you changed it only 5k miles ago, I'm not sure why the belt changing interval would make a difference, thus I think that in your case the belt change interval is not the problem.

Did you use the oil you thought you had, not gear lube by any chance? No reason just changing the old oil with the same new oil should cause such a change in reading, esp since you hadn't changed the filter yet. I think this eliminates a filter problem, since the old filter seemed fine, with proper readings? A problem with the pressure sender or gauge? Haven't heard of a filter causing such a problem, esp with a medium weight lube such as 10W-40 oil.

Maybe a problem with the tensioner adjustment?

Keep us posted.
Thanks, Del.

Will update what I discover with the inspection tomorrow but common factor is the oil change. As said, always use the same oil. Have noticed before that even different brands of oil filter give different pressure readings.
Open to suggestions but can't think of anything else that could have cause it, given the (no pun intended) timings (of events).
 

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In this case, he got a change in the dash indicated oil pressure before he changed the filter "after an oil change and on my way to purchase a new oil filter", using the same brand/weight oil. So, that rules out the filter as a problem with oil pressure. Can't answer why the oil pressure would read much higher after the oil change, if that was the only change. A check with a mechanical gauge would tell the real pressure.

As for the timing belt jumping/skipping teeth, since there was no change in brand/weight of oil and the filter had not been changed (the belt had been changed only 5k miles previously), I don't see any causation from those factors.

I suspect something else, such as tensioner adjustment/setting or belt contamination, if in fact the belt did jump teeth. Or, could there a different reason for the power degradation, unrelated to a suspected timing belt problem?

Looking at this: "Limped car home to avoid further jumps and going to open it up tomorrow to see how many teeth it has jumped; guess two, maybe three on rear bank"

He does not know if the belt did actually skip one or more teeth, but brave person to drive the car home, having that suspicion.

His inspections will tell us.
 
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Driving conditions? I once had it jump teeth(about 16 years ago), always used Agip 10w40 and oem filter. It Didn’t jump from the oil change, slight aggressive driving and engine braking abrubtly was my cause. When I parked at idle it was coughing, this was my indication of jumped teeth after I checked idle air control. Replaced belt, questionable bearings and tensioner. Since that time I’ve used Lubrimoly, Castrol, Quakerstate,Mobile One And Bosch, Oem, Fram etc. Never had an issue with cam teeth jumping again. I had changed method of putting on the belt. With cylinder covers off, I lightly unscrew the cam pulley to camshaft bolts (on all 4 cams), slightly knock off the pulley with plastic mallet from cam. Put the belt on and tighten with special tool to specs. Adjust each cam line to cylinder perfectly and tighten pulley back on. Each one done one by one. I have never used cam locks before. I had the special tool but not the accesories. I later picked up special tool cases 24v, 164 and Alfatester. Still do it my way though
 

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I'm confused. If the engine is showing normal oil pressure, what difference would a filter or the oil make?
 

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After some thought, I don't think this is a pattern. I think it is just coincidence.

The spike in oil pressure? Maybe just a bad gauge sender/gauge or maybe oil pump on it's way out.

These cars slip timing all the time and mainly on cold start (but on start up or stop, they can loosen) up due to not enough belt coverage on rear camshaft pulley. I just think it was time and 10 years was the time. My suggestion do a pressure test as the gauge may just be the issue. I also highly doubt the oil or filter is the problem. Just to rule out your theory make sure to use properly spec'd oil filter.

2 bar higher oil pressure cold and hot? hmm. Again I may suggest bypassing gauge in car and doing a pressure test.

My guess? Timing was not done precisely. Cam pulley washers maybe worn thus slipping. I'd pull valve covers to properly time it.
 

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Discussion Starter #8
Hi guys,
braved the sun today and got under the car. Cambelt is completely fine and timing is bang on. Must have been something else causing it to behave as if a cam had slipped. Not fired it up again yet as doing other jobs while have it 'apart' but overall a huge relief. :)
BTW, am still going to junk the 166/GTV oil filter and drop in the Mahle OC473 one.
Thanks for everyone's input on this. :)
 

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Of course, the weird oil pressure reading was before any oil filter change?

Do a manual gauge check on the oil pressure to see if it still is weird, or is just the gauge or sender.

Finally, go through and clean and lube with dielectric grease the ignition module connectors located below the air filer box. If they get dirty, and they will because they are in the airflow path for dirt and water, they can cause the plugs to misfire and the car will run crummy, so to speak. Had that happen to my LS.
 

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Discussion Starter #10
Of course, the weird oil pressure reading was before any oil filter change?

Do a manual gauge check on the oil pressure to see if it still is weird, or is just the gauge or sender.

Finally, go through and clean and lube with dielectric grease the ignition module connectors located below the air filer box. If they get dirty, and they will because they are in the airflow path for dirt and water, they can cause the plugs to misfire and the car will run crummy, so to speak. Had that happen to my LS.
Hi Del.
The extra high oil pressure reading came as a result of the oil filter change, hence my conclusion this was to blame when I suddenly got cambelt jump like running symptoms. I was driving with no issues with a warm engine on a dry warm day, not stuck in traffic, just changed gear, went round a corner, down a hill and suddenly found the car running like a dog - from nowhere. Exactly as it did when the rear cams did slip in the past.

Still got the car in bits and looking into it, while replacing brake pipes/calipers and other stuff in general. If find any definite cause will post it.

Many thanks :)
 

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Check coil packs and spark plugs, check for oil in spark plug well. Possibly the spike could have forced some oil in to spark wells causing fouling.

Also how did you confirm timing? Just off marks on cam pulley or did you pull valve covers?
 

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Discussion Starter #12
Check coil packs and spark plugs, check for oil in spark plug well. Possibly the spike could have forced some oil in to spark wells causing fouling.

Also how did you confirm timing? Just off marks on cam pulley or did you pull valve covers?
Hi Steve,
great to hear from the guru :)
For the last 80,000 miles I've confirmed cam timing via timing marks painted onto the cams from the original cambelt change - I just touch them up each time for clarity at the next. They were all bang on the same as when set 5,000 miles ago, crank timing mark included.
Avoid undoing the cam wheels from the cams, not just to avoid taking more of the engine off to use camlocks but also because there are several horror stories of undone cam wheels slipping after being reset.

Good point about possible oil in spark plug wells. Planning to changes plugs shortly and will check then, in meantime guess I will know more after restarting it next week.

Cheers :)
 

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Hi Steve,
great to hear from the guru :)
For the last 80,000 miles I've confirmed cam timing via timing marks painted onto the cams from the original cambelt change - I just touch them up each time for clarity at the next. They were all bang on the same as when set 5,000 miles ago, crank timing mark included.
Avoid undoing the cam wheels from the cams, not just to avoid taking more of the engine off to use camlocks but also because there are several horror stories of undone cam wheels slipping after being reset.

Good point about possible oil in spark plug wells. Planning to changes plugs shortly and will check then, in meantime guess I will know more after restarting it next week.

Cheers :)
It's Jason. Steve's the other guy! ;)

Reason I ask is with a tapered camshaft I don't fully trust marks, even if they line up. I always confirm by pulling it all off. it's really the only way if you have experienced any sort of timing slip.

Let us know what you find! Ciao! or Cheers!
 

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Guess I misinterpreted what you said "after an oil change and on my way to purchase a new oil filter". Thought you didn't change the filter until later, but the funny oil pressure readings came on your drive to get the filter. Ok.

Oil is a dielectric in most cases so doesn't cause fouling unless actually on the points of the plugs. Our older 4 cyl Alfas used to run sometimes with oil in the plug wells, and there were no problems.
 

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True but anytime oil is in the spark plug wells it can cause misfiring if there is enough of it in the well. A little in there does not harm at all unless plug is not torque'd properly. I am also suggesting checking the coils in general and ignition modules. Clean and apply new paste.
 

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Discussion Starter #16
It's Jason. Steve's the other guy! ;)

Reason I ask is with a tapered camshaft I don't fully trust marks, even if they line up. I always confirm by pulling it all off. it's really the only way if you have experienced any sort of timing slip.

Let us know what you find! Ciao! or Cheers!
Apologies Jason. Think that's the second time I've accidentally called you someone else over the years.

Understand your point about the risk of taper slip making the old marks potentially inaccurate. Guess it's a judgement call. Car, usually, runs beautifully using those timing marks and if they haven't slipped over 100,000+ miles unlikely to suddenly have done so. Prefer your other suggestions of possible high tension electrical issues. Will look into this once the car is back together - still waiting for new hex head bolts to arrive for my modded serpentine belt idlers.

All the best and thanks for being such a great supporter of Alfas,

Richard :)
 
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