SEAFOAM BEWARE...

[jamfu]

jamfu,

Thanks for the thoughts. My lifter noise sounds identical to what I occasionally hear on a cold start after the car has sat a few days. This leads me to beleive it's excessive clearance, due to one of the lifters not pumping up properly. An overly tight valve would burn in no time, due to not closing fully. Who knows, but my feeling is this is not the case.

"I replaced the pan and oil pick-up o-rings last weekend. The oil pickup screen was free of debris, but the o-rings were aged and brittle."

One other thing I neglected to mention is the spring(s). If in fact you properly replaced the pan and oil pick-up o-rings(you would know immediately though), the problem was still there. I've been using seafoam for years and have never had this problem. I always use the brake booster vacuum line though. Bottom line is that it has to be a clearance issue. Too loose will cause a tick, and too tight will cause a tick as well. I agree that the valve will fail quickly if it is too tight, but it's hard to tell the difference on a multiple cylinder engine until it's too late. And the cyl will still fire if the valve is on the threshhold of not sealing properly. Compression test and valve clearance check will let you know the problem cyl, but it still sounds like a worn out valve seat to me.

[renns]

Thanks for the thoughts, but I'm having a hard time understanding your hypothesis. Is it really possible for that much carbon to exist between valve and seat? I have never seen buildup like that in any engine I've had apart over the years. The impact of closing always knocks the seat area clean. Now build-up on the backside of the valve is another matter. Now even if the valve did somehow drop back another few thousands of an inch when carbon is removed, the hydraulic lifter is designed to compensate.

This noise when a rocker moves too far - is this a known Volvo issue? Seems very odd unless extreme valvetrain geometry problems exist.

[jamfu]

Thanks for the thoughts, but I'm having a hard time understanding your hypothesis. Is it really possible for that much carbon to exist between valve and seat? I have never seen buildup like that in any engine I've had apart over the years. The impact of closing always knocks the seat area clean. Now build-up on the backside of the valve is another matter. Now even if the valve did somehow drop back another few thousands of an inch when carbon is removed, the hydraulic lifter is designed to compensate.

This noise when a rocker moves too far - is this a known Volvo issue? Seems very odd unless extreme valvetrain geometry problems exist.

What you said is pretty much my point. If the figurative stars alight..ie Valve at the upper length tolerance, extra travel from removing carbon, and or weak springs make sense that the lifter is out of its range to compensate. And all deserve merit with a high mileage vehicle. Yes the impact removes the carbon, but remember that carbon is harder than steel. Although brittle, still harder. So, it will wear the seat. Just a few thousandths makes a tremendous difference. And one thing that makes my hypothesis apparent to me is. Before Seafoam(carbon removal) no tick. After there is a tick. I have not heard too much regarding this being a problem with most volvos, but every machine is different regardless of it being the same model make and year. There will always be a percentage of vehicles that just make the passing grade out of the machine shop. It happens with everything. Also, stuff just plain wears out.

[bright]

Renns, I loved the "I do love my Volvo..." I got a good laugh at that.

To be honest, what is done is done. The valve taps. It's a learning experience. It is also one of the many reasons I advocate against using an additive of any sort.

It sounds like you are just killing yourself over a mistake that probably has no short or long term impact on your car. Your car will give you much more immediate headaches than a tapping valve. Think steering rack. Be sure to change the power steering fluid every so often. That is a very expensive accessory that folks just ignore.

Change out your coolant. Flush it with plenty of water. Fill it with distilled water and coolant. You can then feel smug knowing that distilled water will have no nasty carbonates which will give your internals deposits. (But to be honest, they are already there.)

Oh, and get your seats recovered professionally. Shop around. I found a place that's going to do mine for $300 a seat, in leather. Man, that will make you feel like a million bucks. Newly re-padded and re-skinned seats are the cats pajamas.

Best of luck,
Bright
It'll make you forget all about that clicking sound.

[mdempst_79]

Well here goes my $.02

I have 3 850/70 cars, and lots of seafoam experience. I am currently driving a Automatic 97 850 N/A wagon with 410,000km on it. When I got this car (cheap) the owner thought it had lots of problems and was about to die. I replaced the usual engine mounts, sway bar links, cleaned flame trap & Throttle body etc. Once the main work was complete, you could still notice hesitation in the engine between shifts (the computer momentarily reduces torque while it shifts, and re-applies engine power). While it was re-applying the torque you could feel the engine studder and then continue on fine. So looking at the KM on this car, I knew everything must be all dirty and in need of a clean. I bought 2 cans of seafoam...

I drained out the oil, put in some new fresh oil, warmed up the engine and added about 1/2 can of seafoam and let the engine run. Took for a test drive and you could instantly feel the difference, but a slight hesitation still existed between shifts. I decided to add the other half to the engine (I have done on my other cars also). I did the usual procedure as noted on the can (except I used 1/2 can instead of 1/3 tho). Since that treatment, this car now runs quiet starts first rotation of the crank, and doesn't have any hesitation between gears.

What I believe caused the problem that this thread is about, is when you add seafoam to the engine, you don't always have to force the car to stall... when you force the car to stall a lot of the liquid pools in the intake manifold because there is no airflow to mix it up (and it still drains through the hoses leading from the can. After the 10 minute wait, enough liquid can pool inside one or maybe two intake runners, and as soon as you try and fire up the car the first downstroke sucks in enough fluid to hydrolock that cylinder(s).

There was a comment describing how to add seafoam through the brake booster hose... That is correct because that is a large hose allowing a lot of air into the intake while taking in the fluid. You see, when you add it through the vacum tree, there is little air acutally going in through the engine compared to how much liquid is entering.

I swear by seafoam, on all cars.. I have also noticed on my car, that it doesn't excessively smoke at idle any more, which makes me happy.

[renns]

Thanks for the thoughts guys. I've done all I can without disassembling the head to check for faulty lifter or other valvetrain issues. The car continues to run fine, and the tapping is only noticeable with the window down. Given it's Dec. in Canada, the window stays up except when fetching a coffee from the drive-thru!

I understand the risk of a bent rod due to hydro-locking. Given the relatively slow tick rate, and the high-pitched sound, I'm fairly certain it's something in the valvetrain though.

I've replaced sump o-rings, changed oil multiple times, and switched from dino to synthetic, and back, all with absolutely no change. At this point I plan to just keep driving it as-is, and see if the knock gets any worse. I've put on about 3000 km since, and it's been steady thus far. As for Sea-foam, I swear as well, but 'at it', rather than 'by it'.

[FCPEURO]

Honestly, if the car is still running fine, there is only so much you can do. I would just start saving some money up so that if/when this engine goes, you can either drop in another engine or replace the whole car.

It really does stink that you could not get rid of the valve noise.

[bright]

I agree with Groton. You can whip yourself silly (or hire someone off of Craigslist to do that) and still not be satisfied.

Honestly, Seafoam's performance is largely based upon the placebo effect. I'm sure there are people who would challenge me to a knife fight in a phone both over such words (including seafoam.)

Don't beat yourself up. I'll bet that you'll run the car for over a 100,00 miles further before it actually gives up the ghost.

In the mean time other things will get you. Think accesories! A/C pumps, rattling door handles, lights all over the place. The list goes on.

I've said it over and over again. I have rarely come across a car that died due to a bad internally encased engine part. Everything other car I've seen in the junkyard's has been due to accessories going bad. MAP sensors, water damaged ecu's from clogged a/c drains, no climate control, bad windows, crash damage...most of it was an accumulation of smaller problems that sent the car to the yard.

But if it really makes you feel better, replace the head. But I hope that it is worth $1500 of satisfaction.

Bright

[renns]

No worries - I'm not beating myself up, just trying to get a good understanding of what happened. The car doesn't owe me anything at this point, although I'd be pleased to have it with us for several more years even with the tick. If it does choose to expire sooner for some reason, I'll have my chance to upgrade to a T-5!

[whoa]

I believe rolling the windows up was the correct fix. It can also cure some brake noises and suspension rattles.