Piston Slap on Cold Starts

[harbor]

I've noted a few comments on oil type & viscosity solving piston slap.

My daughter's new (last Spring) Dodge Neon exhibits piston slap on cold start up, but quiets down once warmed up. Car has almost 5K miles and runs fine other than this issue.

I broke it in on Castrol 10W-30 GTX last summer, and it currently has M1 5W-30 in the crankcase
(I'm in Michigan winter weather).

Options are:
1) Take it back to the dealer, complain and maybe get a new short block under warranty; but, risk shoddy workmanship of rebuilding a new engine, or
2) Try to quiet it down with a premium oil mix.

Any thoughts? How damaging is piston slap if I let it go?

 

[Patman]

The LS1 engines (that go in Corvettes, Camaros and Firebirds) have some pretty nasty piston slap problems but it doesn't seem to harm their durability at all. Same with some of GM's 3.1 liter engines too.

A lot of guys I know with LS1s have had good luck switching from Mobil 1 5w30 to 10w30, or even to a mix of 10w30 and 15w50. Others have also had good luck switching from Mobil 1 to Redline or Amsoil.

So before you go to the dealer, try out another oil other than Mobil 1. Some cars just don't seem to do well with Mobil 1, at least not the thinner viscosities.

 

[G-MAN]

GM's 3.1 and 3.4 litre V6s are notorious for piston slap. The 3.4 in my Olds van has had it since day one and it's now got almost 150,000 miles on it. It still runs strong, uses no oil between changes, and gets 30 mpg. So, to answer your question, as long as the slap isn't so severe that you risk cracking a skirt, it's probably not going to affect the life of the engine.

As an aside, the slap in my engine is not as loud on cold start and goes away much quicker with Mobil 1.

 

[Al]

I completely agree with Patman. Mobil 1 10W-30 probably won't cut it (it didn't for me). As Patman said the 3.1 is particularly prone to the slap. GM indicated that if the slap lasted no more than 1.5 minutes (I believe) it was OK

My one 3.1 had the slap for 65 K when I got rid it (for the other major problem with the 3.1-its total junk). Redline I believe has improved the slap for one poster. I would take it to the dealer and get a case # for the problem. However Neon engines are not known for their durability.

I also agree with your fear that the dealer will screw it up. I'd wait closer to the "end of warranty date"

I'm sure you want to be conservative since you don't want your daughter to break down on the highway. But its unlikely that the slap wll end up as a catastrophic failure and stop the car dead

Good luck.
You might want to pull an oil sample as further documentation to the problem (if the numbers are bad)

Again if it goes away relatively quickly its not likely to be a problem.

 

[vettenuts]

WOW. I have been very happy with my 3.1 Pontiac Grand Am. It has piston slap, and although I haven't timed it, it goes away when the engine has run. I haven't found 10W-30 Mobil-1 will solve it. Car now has 115,000 miles on it, still runs strong, and has overall been a good motor.

 

[Al]

quote:

---

Originally posted by vettenuts:
WOW. I have been very happy with my 3.1 Pontiac Grand Am. It has piston slap, and although I haven't timed it, it goes away when the engine has run. I haven't found 10W-30 Mobil-1 will solve it. Car now has 115,000 miles on it, still runs strong, and has overall been a good motor.

---

Maybe I'm harder on it than I should be. I had 2 Corsicas and maybe the reliability of these vehicles in general skewed my outlook. If you did not have to replace the manifold gasket ($500) you may have set a record to the planet for going that distance without doing it. Other weak links on the engine is altenators (I'm willing to bet you are not on your origionsl), EGR valves, and computer module. Naturally the Pakard plug wires can go anytime after about 2 miles on the vehicle

. However the 3.1 is definitely a pocket rocket especially '94 and later. I always got a kick of car mags which indicated the engine only "adequate".

I thought the GrandAm was a 3.4 L .

[ January 11, 2003, 10:37 PM: Message edited by: Al ]

 

[mikep]

Ask any late model F150 owner about piston slap and you'll get an earfull! I've got a 2001 4.6 F- series and along with thousands of other Ford truck owners, have the problem too. Early winter morning startups are painful to listen to.

I'm hopeing Shaeffers 701 and a pretty free flowing filter will help. I've got about 4K miles to go 'till I drain the Amsoil 0w-30 and try the Schaeffers.

I agree you should at least get it into the dealer and have it documented. I have an appointment to bring mine in two weeks from today for the problem. Will most likely bring it back for the same problem 2-3 times to make sure it is not missed by the FOrd reps should some major problem pop up after warranty is over.

Mikep

 

[OneQuartLow]

Mikep, I expect you'll notice a change. The #700 made a great improvement for my Jeep 4.0L's piston slap. Here's the sequence I tried:

Castrol 10W30 - loud - previous owner's oil
Castrol HD 30 - better (but that was a warmer climate)
M1 10W30 - loud again
Amsoil 2K 0W30 - absolutely awful
Swapped 2qts (4:2 ratio) for Ams 2K 20W50 - negligible improvement
Schaeffer #700 - almost completely gone!

After a few hundred miles it's the quietest since I've owned it. No more diesel sounds at drive-through windows. The change wasn't immediate which leads me to believe the improvement had more to do with moly than viscosity. I've heard others have had success using Redline to quiet slap so this fits the pattern.

David

 

[Patman]

quote:

---

Originally posted by Al:

quote:

---

Originally posted by vettenuts:
WOW. I have been very happy with my 3.1 Pontiac Grand Am. It has piston slap, and although I haven't timed it, it goes away when the engine has run. I haven't found 10W-30 Mobil-1 will solve it. Car now has 115,000 miles on it, still runs strong, and has overall been a good motor.

---

Maybe I'm harder on it than I should be. I had 2 Corsicas and maybe the reliability of these vehicles in general skewed my outlook. If you did not have to replace the manifold gasket ($500) you may have set a record to the planet for going that distance without doing it. Other weak links on the engine is altenators (I'm willing to bet you are not on your origionsl), EGR valves, and computer module. Naturally the Pakard plug wires can go anytime after about 2 miles on the vehicle

. However the 3.1 is definitely a pocket rocket especially '94 and later. I always got a kick of car mags which indicated the engine only "adequate".

I thought the GrandAm was a 3.4 L .

---

I owned a 94 Grand Am and one of the main reasons I traded it a year and a half into it's lease was because of it's piston slap. Dealer called it normal, Patman called it annoying as hell to own a new car which sounded like a diesel. Traded it for my first f-body, which was a 95 Trans Am.

And that 94 Grand Am's original alternator only lasted about 6 months before it died!!

 

[Al]

Wise move. But now you don't have all of those wonderful experiences.
So what does my son do?? Goes out and buys a GrandAm a couple of years ago. Good old 3.4 (Still sounds like a diesel). Is the 3.4 a bored out 3.1? I assume it is bc if they stroked it they would probably done new rods and maybe eliminated the slap.

 

[harbor]

Thank you for the responses.

I'll try the switch to Schaeffer's #700 10W-30 this Spring and see if it helps.

( Onequartlow - David: Schaeffer's 700 in the 10W-30 weight solved you problem, correct? Or was it something heavier? )

I wonder if adding Schaeffer's moly would also help.

 

[mikep]

quote:

---

Originally posted by OneQuartLow - David:

Castrol 10W30 - loud - previous owner's oil
Castrol HD 30 - better (but that was a warmer climate)
M1 10W30 - loud again
Amsoil 2K 0W30 - absolutely awful
Swapped 2qts (4:2 ratio) for Ams 2K 20W50 - negligible improvement
Schaeffer #700 - almost completely gone!

David

---

Thx for the info! Interesting that the Amsoil S2000 0w-30 was that bad. When I made the switch from M1 5w-30 and regular Amsoil 5-30 to the s2000 0w I thought I was doing a good thing by helping the cold pumpability. After a short while on this board I now realize that is only a small part of the equation.

Can you tell me what filter(s) you've tried? Which one flowed the best if you have those specs?

Looks like there is definetly a case or two of #701 in my immediate future.

Thx again for the info and thx Harbor for bringing this topic up. Even though it is a common thread seems everytime you read about it something new is gained.

Mikep

 

[OneQuartLow]

harbor, The #700 is their 15W40. The 10W30 is #703. Both are from their "Supreme 7000" line.

Bob's analyses showed slight differences in formulation but the moly levels were very close.

I'm also curious if the #132 moly would help.

David

 

[OneQuartLow]

quote:

---

Originally posted by mikep:
Thx for the info! Interesting that the Amsoil S2000 0w-30 was that bad. ...

---

Giving Ams the benefit here, cushioning piston slap isn't a typical lube requirement.

For filters I've used a variety. Mainly Wix, Baldwin, and PureONEs. The Purolators were stock-sized PL14670 and then oversize versions in PL30001 and PL40017. The improved flow rate from additional media is part of the reason. The 14670 is rated at 3GPM, 30001 at 5, and 40017 at 7. It's becoming the Frankenstein monster though as I'm gathering parts for a high-flow dual remote setup.

You might try some of the #132 as well. I'm dying to know how just a moly additive affects piston slap.

David

 

[OneQuartLow]

Checking my records, I need to fix the sequence of my oils versus the piston slap:

-Castrol 10W30 - Loud - previous owner's oil
-Bulk Pennzoil 10W30 - Loud - Quick Change
-Valvoline All Climate 10W30 - Maybe quieter?
-Castrol HD 30 - Better, but that was a warmer climate
-M1 TriSyn 10W30 - loud again for two changes
-Amsoil 2K 0W30 - absolutely awful
-Immediately swapped 2qts for Ams 2K 20W50 - negligible if any change
-Schaeffer #700 - almost completely gone! (So far only I hear a trace)

 

[MolaKule]

Something you might try.

Whatever oil or engine, try about 8 oz. of Schaeffer's #132 Moly Supplement in 4-5 quarts of oil and see if it doesn't reduce piston slap.

My theory is that the two organometallics and the "penetro" base carrier have a cushioning effect on mechanical impulses.

 

[Dr. T]

But, now M-1 has moly in it, so should have the same effect as using Schaeffer's moly or oil after a few changes? Or are the concentrations too low?

 

[ovenrat]

quote:

---

Originally posted by Patman:
The LS1 engines (that go in Corvettes, Camaros and Firebirds) have some pretty nasty piston slap problems but it doesn't seem to harm their durability at all. Same with some of GM's 3.1 liter engines too.

A lot of guys I know with LS1s have had good luck switching from Mobil 1 5w30 to 10w30, or even to a mix of 10w30 and 15w50. Others have also had good luck switching from Mobil 1 to Redline or Amsoil.

So before you go to the dealer, try out another oil other than Mobil 1. Some cars just don't seem to do well with Mobil 1, at least not the thinner viscosities.

---

Thought I'd chime in here.....have an 02' F150 5.4L V8, had the piston slap from day 1 (Motorcraft 5W-20 semi syn) "UNTIL" I started to use Mobil 1 SS 0W-30, M1-210 filter at 5800 miles. Now at almost 11,000 and quiet as a mouse, who's to figure?

 

[Al]

quote:

---

Originally posted by Dr. T:
But, now M-1 has moly in it, so should have the same effect as using Schaeffer's moly or oil after a few changes? Or are the concentrations too low?

---

Mobil 1 10W-30 SS didn't quiet my son's 3.4. Neither did the 5W-40 Delvac 1

 

[mikep]

quote:

---

Originally posted by Dr. T:
But, now M-1 has moly in it, so should have the same effect as using Schaeffer's moly or oil after a few changes? Or are the concentrations too low?

---

But according to what I've read here isn't M1 Xw-30 on the light side of the viscosity range? If so, I'd think that would sort of offset the moly factor or at least marginalize it. Then again, ovenrat has been having success with it. Lord, the more time I spend here the less I realize I know.

SeldonT....glad to know the problem doesn't seem to have had an effect on engine life. But if mine made that god awful sound for 30-45 seconds I would surely go insane. I can't stomach the 5-6 seconds that my truck clanks. What filter are you using?

This is turing out to be a love in for F-Series owners

.

Mikep