Seemingly Negative Experience adding Seafoam to oil. 5.3 Yukon

Status
Not open for further replies.
Joined
Aug 26, 2009
Messages
3,016
Location
PA
I added Seafoam to the oil (M1 0W30 AFE) in my 02 Yukon XL. 5.3 LS engine, 175,000 miles. It has the common piston slap, a rather severe case.
Even hot it has a slight bit of it, sometimes I wonder if it is a lifter tap. The truck runs great though and hardly burns a drop of oil. The noises have remained the same for the past 15k, since I got it. After watching a page called Project Farm, seemingly do an unbiased test, Seafoam in the oil quieted down the valvetrain in the test truck. (Video below). Seafoam won't help piston slap but a lifter issue it may.

Prior to the addition of Seafoam, my oil was at 5300 miles and was a clear amber. I added 6-7 oz of Seafoam and put a couple hundred miles on a few days. No changes, aside from slightly darker oil on the dipstick. I had written it off as not effective. 5 more days and I'm past the 400-mile mark, planning to change the oil somewhat soon. I picked a girl up to get lunch and do a few other things. While I'm waiting for her to come outside I notice my hot idle oil pressure is down. About 4 pounds down. I can't trust the OEM gauge for perfect accuracy but it was lower than normal. I shut it off, check the oil, it's full and a bit darker. She comes outside while I've got the hood up wondering if everything is ok. I tell her I was just checking the oil since I was waiting so long...

We drive about 30 minutes and when I park my idle oil pressure is even lower than before, I'm at 23 instead of my usual 29. I get out and I can smell that hot engine smell as I walk past the front. Smells like when an older car that is running low on oil or a car with an electric radiator fan that isn't working and is running a bit warmer than usual. Also noticeable is all the metal noise "tinking" cooling down, like an old car or motorcycle would do. My coolant temp was normal. I feel fairly certain the Seafoam was creating extra friction or had thinned out the oil too much.

Eventually, I got it home and drained the oil, no debris came out, nothing suspect was left on the bottom of my clean drain pan.

PP 10w30 went in. Full heat soaked hot idle oil PSI is back to normal.

Perhaps it was coincidental, I'm fairly skeptical though. The engine was not liking something and if I didn't add the Seafoam I would have ran that oil for another 2000 miles easy.
 
Originally Posted by Gasbuggy
I picked a girl up to get lunch and do a few other things...


Forget the Seafoam, how did this work out??
cheers3.gif


Did you think about using the Lucas product?
 
Originally Posted by AZjeff
Originally Posted by Gasbuggy
I picked a girl up to get lunch and do a few other things...


Forget the Seafoam, how did this work out??
cheers3.gif




Ha! That was downright hilarious.

To the OP: If the oil got quite a bit darker I would say the seafoam cleaned out the engine and probably helped.
 
The Seafoam probably thinned the oil, a lot which would explain the oil pressure drop. I wouldn't add Seafoam to the sump for that reason. If for some reason I did, it would be for a idle flush only, no driving the vehicle and no more than 10 minutes in the sump.
 
Did the lifter noise (or other noise) go away after the seafoam? I have had mixed results with it...very effective in my lawn mower but not in cars. Kerosene or Motor Flush for a 10 min idle (as demarpaint suggested above) seems to be as effective as anything else ive tried for reducing lifter noise.
 
Just curious, Did the tap go away? For my last BMW, I ran 20w50 dino year round. Come December, I would add a pint of MMO to oil. Granted all the car has is an idiot light. But there were no strange smells or sounds. I couldn't even smell the wintergreen when I sniffed the dip stick. I know, Adding MMO to oil is OLD school. The bottle says it can used up to 20% in oil. I used 1/2 of that, 10% . It was enough to allow the car to start at 0F. It rarely gets to zero here, due to the ocean. Going to 10w30 is a step in the right direction. The take away from using Sea Foam is that the insides of the 5.3 are squeaky clean. No need for any more flushing.
grin2.gif
 
The Seafoam did it's job by the color change. 29 hot idle down to 23, no biggie ... If it had dropped to 10 I'd be concerned. It came back with an oil change, all is good.

So, with 170K on it, why not switch up to 15W-40 HDEO? It should help with the piston slap some. Still thin enough to cold start easily. Seems like the next logical move ...
 
Originally Posted by BrocLuno
The Seafoam did it's job by the color change. 29 hot idle down to 23, no biggie ... If it had dropped to 10 I'd be concerned. It came back with an oil change, all is good.

So, with 170K on it, why not switch up to 15W-40 HDEO? It should help with the piston slap some. Still thin enough to cold start easily. Seems like the next logical move ...

Why run a 15w-40 just because it has high mileage?? I'm running 10w-30 on my 276k Silverado and I'm actually gonna go down to 5w-30 next time so I can run the same oil in both my vehicles.
 
Originally Posted by andyd
Just curious, Did the tap go away?



He just said "He picked a girl up to get lunch and do a few other things..."
 
The piston slap/knock is due to hypereutectic pistons that expand as they warm up, which is why it quiets down after a few minutes of run time and is worse in colder weather

drive it another 200K miles.
 
Originally Posted by krismoriah72
The piston slap/knock is due to hypereutectic pistons that expand as they warm up, which is why it quiets down after a few minutes of run time and is worse in colder weather

drive it another 200K miles.


No, the slap is due to bulk-fit pistons with short skirts. Hypereutectic pistons, by virtue of their silicon content, expand/contract less than forged or cast slugs. Part of the reason for the development of hypereutectic pistons was to be able to tighten up the piston/wall interface for less blow-by and superior emissions performance.

Now, the reason they quiet down is indeed due to the pistons expanding, but the scenario would play out the same regardless of piston material choice.
 
I've run seafoam in the sump for entire OCIs in used high mileage volvos, among others. never more than half a bottle and never less than a 10-30 oil. I've seen it slowly help clean them up; it's no miracle but helpful in small amounts. Over time, consumption in one of these went from 1 qt every 1000 miles to 1 qt every 7500 or so. If I use the whole bottle, it's only to idle for an hour as a flush, or the last 500 miles (gently) before an OC.
 
This got quite a response! The tap didn't go away or change pitch. It's my loud piston. This truck piston slaps so bad on a cold morning that it triggers the knock sensors. The worst LS engine slap I've heard. People stare at you when it starts up cold. I think its kind of funny. I plan to try Mobil Delvac 15w40 on the next change. (I bought 10 gallons during that $7 a gallon rebate they had) but viscosity doesn't seem to impact the piston slap. I've run Maxlife 10w40 before. With the supposedly cold winter coming, I decided to use a 30wt for this change. I did add a full bottle of Liqui Moly MoS2 to the PP, we'll see if that helps anything. I've never really messed around with oil additives in my cars before.

I'm a lot smoother than my engine so the day date went well. pic of the girl sitting in the Yukon.


[Linked Image]
 
I was hoping my reply would be the first post of page 2 not the last of page 1. Oh well
 
I've used 1 oz. of Seafoam per quart of engine oil and ran for 100 miles or so before an oil change with no engine issues other than the dipstick was darker than before the Seafoam went in ... If it concerns you then ditch the Seafoam (but not the girl - she is a keeper !)
 
Cute girl, I'd have used the CTS-V in your sig instead of that land yacht hunk of GM junk! lol.

Sea foam did what is was supposed to, darker oil meant it was cleaning and doing its job. However, I never use a thin grade oil when I plan to add a solvent based cleaner like Seafoam... you should go with a 15W40.
 
I have a 2002 Tahoe 5.3L with 237k miles. It's had piston slap since day one, though it only did it on cold starts. What worked for me was switching to an oil with high amounts of moly, especially tri-nuclear moly. I ran Amsoil Signature Series 10w-30 for a while, which has around 240 ppm, and it quieted down a good bit. I recently switched to Driven LS30 5w-30, a PAO/ester oil with around 400 ppm of tri-nuclear moly, and the piston slap is gone entirely. Even with it being 30*F out this morning with frost on the windshield, it still fired right up smooth and quiet.

Keep in mind that just because the oil turns darker doesn't mean it's cleaning. Oil turns black from oxidation. Seafoam is highly susceptible to oxidation. If you added seafoam to engine oil in a container and let it sit on a table for a few weeks, it would turn dark as well. The naphta and mineral spirits in Seafoam will attack the base oil (particularly nitrogen sites), turning the base oil black. It gives the illusion that it's working when in reality it's just smoke and mirrors. It affects the base oil in the same way as fuel dilution.

Unrelated to Seafoam, some ashless dispersants turn dark due to UV exposure (from combustion events) making the oil appear oxidized when it really isn't.
 
Last edited:
Status
Not open for further replies.
Back
Top