Hi everyone, happy holidays!

I was just wondering if anyone has experienced this before: Sometimes my B230FT makes a piston slap noise when it is warm. It has some 'piston slap' when it is cold, but for the most part it goes away once the engine has warmed up. ALTHOUGH, sometimes when I step out of the car when the engine is running and warm I can make out a slight piston slap like noise. This puzzles my Volvo mechanic as well as me. The engine was totally rebuilt about 8-9K km ago. Before the rebuild it had what I would call severe piston slap that was still quite loud even when the engine was warm. I am hoping that my Volvo's engine is not trying to go back to the way it was. The only internal parts that were not replaced during the rebuild were the crankshaft and the connecting rods (13mm), those five parts did not show any wear. Oh, and just so you know, the valves were adjusted after the rebuild and the oil pressure was tested. Anyway, I'm just wondering if I should be concerned about this occasional 'piston slap' when the engine is warm or if I should just forget about it? The engine has been running on Amsoil 10W30 for the last 1K km or so. Thanks in advance for your input.
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Chris. Halifax N.S. '91 745Ti, 268K km.

I've had the same problem with my car since i got it three years ago. It has 152k on it and i have done all kinds of work to solve the problem. No matter what, it always comes back. I just don't worry about it now. Pointless.
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-Brandon at FSU '88 744ti 150k miles

What kind of oil do you run in your B230FT? Have you tried different kinds?
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Chris. Halifax N.S. '91 745Ti, 268K km.

Volvo techs all over the world chased down piston slap. They put in new pistons, they did it all. But in some engines, it never ceased. The longer pistons (longer skirt) apparently curbed the problem, but I doubt it curbed the problem entirely. The only remedy in some engines is to replace the whole engine.

Piston slap when warm is not uncommon either. I see it frequently on Turbo cars. However, it could also be a knocking water pump. Unless you just replaced the water pump (not exactly like piston slap, but a rapping noise nonetheless) check play in the pulley. The knocking can be bad. But that isn't usually the cause... piston slap is pretty common.
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Chris Herbst, in Wisconsin.

Hey Chris,

I'm happy to hear that this is normal even for a freshened B230FT like mine. It puts my mind at ease. Do you think it will get worse? Do you think I should continue to use Amsoil or should I try Mobil 1 at the next oil change. My Vo mechanic is stocking Amsoil mostly for me, but if it's hurting my engine I'll try Mobil 1. The water pump was replaced during the rebuild with a completely new pump. My mechanic did a major job on my engine. He replaced many parts including sensors, vac lines etc. He even moved my distributor to the front of the engine (old style) and totally repainted the block, and sand blasted and painted the oil pan, turbo lines, etc. It looks GREAT. Too bad it still slaps...Oh well, it's not nearly as bad as it use to be at least and I hope it stays that way!
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Chris. Halifax N.S. '91 745Ti, 268K km.

Some of them were just slappers. It isn't technically "right", but as long as it isn't a big knocking, it shouldn't be that big a deal. It's stupid that the engines would slap like that, but some of them just did. And some of them never ever do it. I don't know exactly what determines which ones do and which ones don't.

As for the oil choice, someone from the board just mentioned that Mobil 1 0w40 had all but eliminated their scratchy sounding piston slap on a B230FT. It might be worth a shot to see if it does anything.
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Chris Herbst, in Wisconsin.

The Master Volvo Tech whom I know says he did lots of custom piston fitting to eliminate piston slap on cars under warrantee. He adds that piston slap issues stopped when piston oil cooling was introduced in the mid 90s.

John - please help out with my response below. Thanks.
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http://www.fidalgo.net/~brook4/oilslubesfilters.html

How did I do?

My 93 940 T is slapless, but all the rest are slaphappy. I rebuilt one engine, a 90 and it slapped like crazy. Took it out and found out my machinist had done the machining re something other than Volvo specs. The engine (in Gordons car) was sleeved and I reassembled. Result: nearly slapless. Wifes 91 just loves to slap cold or warm, but does it go!!

dick

The 1993 engine may be piston oil cooled and probably has the longer skirt pistons. As to the engine in Gordon's car, these engines are quite intolerant of excessive piston to cylinder wall clearance.

You mentioned you're running amsoil.... I have a freind who used Amsoil oil and filter in his car and it was significantly noisier while running..... he switched back to Mobil1 oil and filter and the noises went away... (both oils were 5W30, the reccomended for that car)

Cliff Scott
89 740 16v <-runs on 5w30 mobil1 and a bosch filter.. well, when it's together

Hmmmmmmm....Interesting. I wonder why Amsoil made the engine noiser then Mobil 1 did? Before I started using synthetic I did quite a bit of reasearch as well as listened to people's opinions and I concluded that Amsoil was a slightly better product then Mobil 1. Maybe I was wrong?! I hope these noises aren't telling me that the Amsoil is causing abnormal damage to my engine. It did make just about the same noises when it was being broken in on dino Penzoil 10W30. I expected them to go away when I switched to synthetic. To my surprise, they stayed and also didn't get any quieter when they occured. Maybe I'll have to try Mobil 1 10W30 at my next oil change.............Oh, I always use a MANN filter, no matter what oil is in the engine.
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Chris. Halifax N.S. '91 745Ti, 268K km.

First let me calm your fears about Amsoil "causing abnormal damage to my engine".....It's not. How many 100's of 1000's miles have I run, Dick from Falls Church, and lots of other Volvos (and more other makes) - My 240 turbo alone has 234,000 miles - zero piston slap!

Sure Mobil 1 has Mo in it but: a) the wear rates and wear metal levels in Mobil 1 are not lower and b) Mo in oil as only an extreme "just in case" antiwear agent - it has nothing to do with Volvo piston slap. Amsoil uses ZDDP as it's extreme antiwear agent. Both somewhat coat surfaces - but neither do much for piston skirt slap.

Now let's get to your problem. Here's a clue:

"It did make just about the same noises when it was being broken in on dino Penzoil 10W30. I expected them to go away when I switched to synthetic."

I have heard synthetic oil quiet lifters and such because it pumps up sooner. I rarely hear that synthetic oil quiets piston slap as the others have mentioned. I am sure that some oils may seem quieter. Try a range. Don't forget Amsoil 15W-40 (in my experience a "quiet" oil).

Now, please post some specs. ALL new parts (except crank and rods). Did he bore and use oversize pistons? What sizes? How was the wrist pin fit? Did he use the long skirt pistons? What brand?

Have you listened with a mechanic's stethascope?



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http://www.fidalgo.net/~brook4/oilslubesfilters.html

Hey Pablos, I was waiting for a Amsoil guy to speak up :) I'll tell you what I know about what was done to my engine as far as specs go: It was bored 0.30 over and oversized 0.30 Mehale (sp?) pistons were fitted and installed. They are not the long skirt pistons. My mechanic could not get them from his supplier and we didn't bother pricing them from Volvo (probably should have). He said the wrist pin fit seemed to be fine (nice and tight) during reassembly. The head was plained 0.10, to give a minute boost in compression. We have not listened to the engine with a stethascope looking for the 'slap' sound. My mechanic did listen to the engine trying to find another noise, but it turned out to be a bad PS pump (it was outside the shop at night). He did not mention hearing the slap at the time (although we could hear it a bit without the scope). Should I try Amsoil 10W40? I'd rather not use 15W40 if I don't have to. My mechanic suggested trying a "Molylube" synthetic 5W40 or 10W40 that he can get from his parts supplier. He said is supposed to be real good stuff. Should my engine be ok with the Amsoil 10W30 in it for another 3-4K km (~2500 mi) or should I try something different sooner? I hate hearing that slap, it makes me feel like my engine is hurting itself......also, it's possible that it's becomming more noticeable, it could just be me though. Seems like it *may* have been a little quieter with the Penzoil dino oil in it............. Thanks for the help.
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Chris. Halifax N.S. '91 745Ti, 268K km.

I know you don’t want to hear this but I have come to the conclusion that there are no good (extra) noises when it comes to things automotive. Normal piston slap in a Volvo isn’t instant death, but I’ll bet it doesn’t extend engine life. If it seems to be getting worse so rapidly in a fresh engine, something is wrong, and it isn’t the oil.

I am NO expert on the “normal” piston slap associated with the late 80’s early 90’s Volvo motors. It is associated the looser, lighter motors designed to increase MPG. I have heard some issues ranging from the confirmed longer piston skirts helping, the lighter crank motors be prone, to the problem decreasing with the 94 et al motors with cylinder wall oil squirters. Some motors even had out of round bores that indeed did not clean up with an overbore and oversize pistons.

0.3mm is 0.012”, first normal oversize. Mahle are OEM quality.

Head planed 0.1 mm (0.004”) shouldn’t change things much…..hmm…

Go ahead and try some other oils. Yes try the 10W-40. Maybe an oil loaded with Moly such as Redline may help. Does your mechanic have a Moly additive just for a test? (I don’t really believe in long term “homebrew” oils, though, but it’s worth a shot.

Get that stethoscope out, just to confirm.

You know who is great at this engine? John Sargent. I’ll page him.
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http://www.fidalgo.net/~brook4/oilslubesfilters.html

I don't know if CW will read my response to you, but I hope he does.

The B230 engines are very untolerant of excessive piston to cylinder clearance. This is due to the short piston design and how the piston clearance (or lack thereof) keeps the connecting rod centered on the rod throw of the crankshaft. Have you ever looked at the connecting rods installed on a B230 engine? There is considerable clearance between the sides of the connecting rod and the crankshaft. This is the big difference between the B230 engines and the earlier B23/B21/etc. The B23/B21/etc engines have a precision fit between the sides of the connecting rod and the crankshaft.

One of the mechanics at my favorite independant Volvo shop, MVP, had an engine overbored for use in his wife's car. The engine has piston slap noise. The mechanic told me the piston to cylinder wall clearance is within limits, but at the maximum allowed. That is probably the cause of the noise in CW's car.

The noise is not from the synthetic lube. Two of our B230FTs use synthetic lube (Amsoil) and have no piston slap noise. It is possible some noise is generated at under cold start comditions because the synthetic lube is thinner than dino oil at the cold temperatures when piston to cylinder wall clearance is greatest.

Thanks for the explanation John. What do you suggest I do? Should I run Amsoil 10W40 and forget about the piston slap? Should I continue to run Amsoil 10W30? Or should I use Amsoil 15W40 to make a thicker layer of oil at cold start? Do you think the piston slap will become worse (if so, any idea how long/fast)? I have some pics of my engine throughout it's rebuild process. I do have a pic of the bottom of the engine with the crank and rods installed. As well I have a pic of the new pistons in the block along with various others. I'll be sure to show your post to my Volvo mechanic (I'm sure he'll be interested). I want my B230FT to last long and run well, so the advise is helpful! Thanks :)

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Chris. Halifax N.S. '91 745Ti, 269K km.

I would run the 10W30. Dick has had a similar experience with and overhauled engine that now runs without noise after being sleeved. The engine pictures won't help. Did someone record the cylinder to piston clearance? To further support my argument about excessive piston clearance, the shop manual lists piston clearance of 0.002-0.0028 for the B23 while the B230 is listed for 0.0004-0.0012.

Hi John,

To the best of my knowledge the cylinder to piston clearance was not recorded. So you think I should continue to run the Amsoil 10W30 and just forget about the slap? Or are you saying that the engine has to be torn apart again and sleeved? Do you think my engine will go a long way as it is? The car has almost 270K km (168K mi) on it now and I'm hoping to drive it to at least 500K+ km (300K+ mi). I'd like to put more kms on it if I can keep the body in good condition. Thanks again for the help :)
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Chris. Halifax N.S. '91 745Ti, 269K km.

It is not my car and I can't hear the piston slap from here, so I can't make those decisions. Dick Reiss ended up taking his engine apart and having it sleeved to cure piston slap after having the cylinders bored.

Ok John, I understand. Thanks very much for the help/advise. I'll probably just leave the engine alone and see if the slap becomes worse in the next several months. I may try Amsoil 10W40 at the next oil change to see how it likes that. If 10W40 gives good results, I'll run it with that. I may just stick with Amsoil 10W30 though, I'll have to talk it over with my mechanic. Oh, I recieved the Cherry turbo 700/900 chassis brace kit for Christmas, so I'm excited to get that installed. Maybe, tomorrow. I'll be sure to show my mechanic what you've written. Thanks again for your help :)
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Chris. Halifax N.S. '91 745Ti, 269K km.

Hey Pablos,

Just got back from town in the Volvo. She wasn't too noisy tonight. It was a little slap happy when I started it after I washed her and was letting her warm up before I left. Just about every time I start it if it's been sitting for more then 10 minutes or so it has noticeable slap. She had a little ticky ticky when she was warm tonight, but it was hardly noticeable. I didn't drive it hard and probably didn't rev over 4000 or so the whole time I was driving her tonight. Maybe that has something to do with it? I'm not TOO worried. If the slap gets progressively worse my mechanic will back up the work, so if say it's back to the way it was (pre-rebuild) in the spring she'll probably get torn apart again and I'll possibly donate some extra $ for the long skirt pistons. We'll see. I won't do that if I don't have to though. Anyway, *maybe* the slap isn't getting worse, maybe it's just seems (or is) more pronounced sometimes(?) I don't think my mechanic has a moly additive, but I could try that 'Molylube' synthetic oil (have you ever hear of it?). Is it possible that my Vo's engine will go on slapping just about the exact same for the next 100K+ mi? Is does piston slap get worse over time? I'll have to get my mechanic to put the scope on the engine soon, maybe later this week. Thanks for the help so far!
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Chris. Halifax N.S. '91 745Ti, 268K km.

We have a 94-940T, as well as a 92-940 N/A, and a 97' 960. Try Mobil 1 0W40. This is factory fill in many new Mercedes-Benz engines, as well as some others.

In the 94 turbo at the beginning of this winter while running Amsoil 0W30 there was a distinct noise when the engine was cold. Amsoil does not use molybdenum as an additive.

After a change to Mobil 1 0W40, no noise - period. So far I am impressed with this oil. Gas mileage seems unaffected, but then again it's winter. Oil analysis later will show if it is performing well IN THIS ENGINE, I think it is but only analysis will show me the numbers.

I personally believe it is due to the molybdenum additive in Mobil 1. One of moly's functions is to act as an extreme pressure barrier, preventing metal to metal contact. The moly is "taken up" by surfaces that are in metal to metal contact. Once it plates up it helps to prevent metal to metal contact.

I might add that the Mobil 1 30 weight oils, are at the bottom limit in viscosity for a 30 weight.

30 weight viscosity oils range from 9.30-12.49 cST 100C
Mobil 1 30 weights are 9.8 approx.
Castrol GTX 10-30 is 10.9 approx.

40 weight viscosity oils range from 12.50-16.29 cST 100C
Mobil 1 0W40 is is 14.6

Molybdenum seems to make a difference. Redline oils contain over 500 ppm of moly. I have some on hand that will be the next fill for my 92' 940. This one has a pronounced piston slap when cold.

I have used Mobil 1 10-30 in my vehicles in the past and oil analysis revealed that engine wear was just average in most respects, and I mean just average when stacked up against all other brands of regular old petroleum oil. My goal is engine longevity and wear numbers lower than average.

I have a 92'940 (before longer piston skirts) and it has a pronounced piston slap, but only when cold. Based on a 90% piston slap reduction reported on another forum when using Redline oil, I purchased some. It hasn't been put in yet. Redline oils contain over 500 ppm of moly.

From oil analysis results in my both of the 940's, 30 weights just don't seem to cut it when it comes to wear numbers on the internals. Okay, numbers, but I want below average wear. Every oil that I have ever used seemed to be good. Just change it out every 3 thousand miles. Oil analysis produces the real evidence - how it performs in that particular engine. I was surprised at the results.

That is why I am moving up to a 0/5W40 weight synthetic oils. Real good winter starting, real good high temperature, high shear protection especially in the turbo.
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92-944, 94-944, 97-960 - Silverstar headlights, Green Diamond Tires

Hi,

I have heard about Mobil 1 30 weights being 'weak' before. That is part of the reason why I decided to go with Amsoil. I don't know if I can get Mobil 1 0/5/10W40 around here. All I have seen is 5W30, 10W30, and 15W50. I don't know where to get any other weights....... I was planning to use Volvo's recommended change interval (5000 mi) with synthetic mostly because of the added cost of the oil. Is this too long? I, nor my Vo mechanic is aware of anyone who does oil analysis around here so that is kind of out of the question. I thought my engine was safe with Amsoil 10W30 in it, but now I'm not so sure. What about if I used Amsoil 10W40? Hmmmmmm.....I'm not sure what to do. I know one thing though; I don't like those sounds comming from my engine! Oh, I'm also not aware of a place where I can get Redline. It may not be available here......
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Chris. Halifax N.S. '91 745Ti, 268K km.

Chris I think Amsoil 10-40 is a good oil, and I will be using some of it in the future.

In trying to address the piston slap, however, I would use the Mobil 1 0-40, for an over the counter product.

I understand that Redline and some of the other synthetics can be inordinately expensive in Canada, I have heard that from some of my Canadian friends.

Try to search out who has the Mobil 1 in the 0-40 weight locally, I know you've got that grade up there.

Chris try out "bobistheoilguy.com" Once there go to the "forums" and you will find a lot of information, including Canadian suppliers for a variety of specialized lubricants. Lotsa Canadians are members of the forum. This forum is where "oil talk" is at - big time.
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92-944, 94-944, 97-960 - Silverstar headlights, Green Diamond Tires

Thanks boysarge! I'll check out that site. I'll try to find some 40 weight Mobil 1. Would 5W40 or 10W40 be ok? My Vo mechanic going to think I went off the deep end after all the work I when through to decide on Amsoil. Now I'm changing my mind. LOL. Oh, what if I can't get Mobil 1 40 weight. Should I try Amsoil 10W40 or 5W40?
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Chris. Halifax N.S. '91 745Ti, 268K km.

as onw who runs mobil 1 0w40 the only thing i can say is - if you have ANY leaks fix them first! this stuff would find itself out of a lobsters backside!

other than that all i can say is my 940t never seems to get hot, sounds ok and goes like stink (especially since its eating 1/2ltr per 150 miles via the intercooler...)

Yeah, it sounded strange to me aswell, but that's how it was... don't know how or why, but a change to new mobil 1 cured the noise,,

Cliff Scott
89 740 16v