Do lifters bleed down easier on an engine that sits if you use synthetic oil?

I have heard this is the case and have experienced it on a couple of auto as well as a mower engine with hydraulic lifters. The mower takes quite a bit of cranking to pump the lifters up and start, then it ticks for a while.

I have one truck that will tick for a bit after you start it if it has sat long at all. Then I had a car that sat for 2-3 months because the clutch was slipping and the weather and my schedule didn’t cooperate for me to replace it. This one didn’t even have compression when I cranked it over for a while. I had to pump the lifters up before the valves would open. It ran bad and ticked for a few minutes, then was perfect.

I have been told by several that this is one of the negatives of synthetic oil, although not a horrid thing. The fact that it flows better at cold temps also means that the lifters bleed down easier.

Anyone else experience this?

The fact that it flows better at cold temps also means that the lifters bleed down easier.

Not sure that logic makes sense. Lifters bleed down after you shut off a running (ie hot, not cold) engine. And if synthetic flows better at cold temps, the lifters should pressurize faster on a cold start, not slower.

Scroll way down to get to the hydraulic lifter diagram:

All lifters lose pressure when the engine is off. It’s hard to see how oil can literally drain out of a lifter. I’d say “lifter bleed down” is really the failure of oil pressure to come up quickly after engine start. This could be caused any number of ways (including badly worn lifters, I suppose).

Lifters can lose pressure. I suppose a thinner oil could do it faster, but it will happen when it sits.
The big question is how fast they can pump back up. Make sure your oil filter has an anti-drainback valve. Synthetic flows better when very cold, so that should help too.

"Anyone else experience this?"
No… No noise at start-up, cold or hot or otherwise, running Mobil-1 Extended Performance, in several cars for many years.

Sounds like a lifter problem to me.

I’ve been using synthetic in all my cars for at least 20, maybe 30 years and have never had lifter noise.

Yup, licky stifters… um, I mean, sticky lifters.

An engine idling cold at 1200 rpm is cycling the hydraulic lifter past the passage that allows the oil to pass into and fill the lifter 10 times every second. If it’s still clickin’ after a few seconds, than you probably have sticky lifters. Or worn parts. Or gummed up passages. Or low oil pressure. Or you live in North Dakota and it’s -40F. Or somethin’ like that. It should not be happening due to the use of synthetic.

“Sounds like a lifter problem to me.”

I agree. I will say though that I tried synthetic oil in my riding mower and it clattered like an old jalopy. I changed back to dino oil and it’s still running smooth. It may just be an anomaly or there may be some reason for it.

The issue with the cars was on engines that had sat a month or more. This might also be an issue with any engine with any oil. It hasn’t happened since that first start after the clutch replacement. Another issue is that the engine calls for 5W30 and I had 0W30 in it. That might also help.

As for the riding mower, we all know that the tolerances in air cooled engines are not what they are in a water cooled one as temps are not constant. Maybe that is part of the issue. Either way, the rest of the engine seems to really do well on the synthetic so I am sticking with it. Without the synthetic, it would smoke some on a hot day if you really bogged it down in heavy grass. The synthetic doesn’t do this and I don’t have to add oil between changes.

It ticked a little after sitting a few days but nothing like after it had sat most of the winter.

My first guess would be that the filter is draining down which results in air being pumped into the lifters at start up and with the metered oil flow to the head it takes considerable time to purge the air.

Any oil filter that is mounter sideways can drain if the anti-drainback valve isn’t good.

5W30 vs 0W30 might explain it all.

I agree that the anti-drainback valve may be causing this. Try a different brand of filter perhaps? I think the cheapest Fram filters don’t even have this feature. Try a Wix, Purolator, or one of the “premium” Fram filters.

I have only experienced the lifters leaking down on a car if it sits for a month or more without being run, and I’ve been using synthetic oil for the last 15 years, though I have personally experienced this problem with cheap Fram filters and the no-name generics that quicky oil change places use sometimes.

Ok, maybe I wasn’t clear. All the cars with this issue had been sitting for 2-3 months or longer. This isn’t something that happens every morning at start. The mower was fine today when it was started.

I am pretty sure I have a decent oil filter on these. I usually run a Wix or Mobil 1. I have run Frams but only the upgraded models and only when something else isn’t available. I will also run AC Delco or Motorcraft.

Well, if a car sits for months, it’s going to happen. When it’s happened to me, the tick has gone away pretty quickly. (within about 30 seconds) If the engine is sludged up or worn of course (as I’m sure you know), it might leak down quicker or take longer to pump back up.

Short answer, they may leak down quicker, but they do not leak down more. Regardless of the type of oil, the lifters leak down pretty quickly due to the pressure put on them by the valve springs. Within a few seconds, or less, they have leaked down as much as they are going to.

Synthetic oil will help build up pressure faster when the engine is cold because it flows easier at cold temperatures. If the oil pressure is not building up quickly, then that is most likely doe top the oil filter not having a good anti drain back valve. The oil filter empties so it takes a while to fill back up when the engine is restarted.

I have an update on these engines. The car that had the lifters bleed down has been back in service several months now after that incident. The lifter bleed down was obviously related to the time it sat before my schedule and the weather cooperated for me to change the clutch set out with a new one. It has run like a champ since with no repeat of this situation. It probably hasn’t sat more than a few days without being run.

The mower stopped doing this after my springtime oil change. I don’t know as the old oil didn’t look that bad but I am guessing it was broken down or getting too thin from shear. Either way, if the riding mower starts ticking on startup, I will take this as a sign to change the oil! I used the exact same type of oil as before so that wasn’t the issue.

My experience on a car with a mild lifter problem, was that it would bleed down a little faster (a few days instead of a week) with synthetic oil, but it would also pump back up faster with synthetic, especially in cold weather. No, I didn’t have cheap filters.