Keeping a 1.8T engine Sludge-free - Seafoam as a preventative?

[DPDISXR4Ti]

Clearly the #1 thing to do to keep your engine from "sludging" is timely oil changes with full-synthetic oil. But just to be over-cautious, I'm wondering if I should do a Seafoam oil treatment 1000 miles before the next oil change. Current mileage is 132K and I did have a little oil consumption for the first time with my recent 5K-mile oil change. Any thoughts on this, or any other anti-sludge magic treatment?

[MetalMan]

Does it have any history of sludge? If not, I wouldn't even worry about it.

But if you are concerned, you could do Seafoam maybe 100 miles before the oil change. Seafoam isn't an oil replacement, so its lubricating properties are inferior to oil, and you don't want to diminish lubrication for long.

[PSI NRG]

To prevent sludge you have to get to the root of where sludge comes from. Over time oil gets contaminated with coolant, fuel, water, dirt etc so obviously changing the oil at a reasonable interval will help keep things fresh. Next, oil over time breaks down or oxidizes from extreme heat. The little fire breathing turbos on these cars can super heat the oil and accelerate break down and oxidation. So to prevent super heating the oil or "cooking" it you need to keep it flowing and allow the cooling system to do its job. This is all fine and dandy while the vehicle is in motion or running. Where it becomes an issue is when you shut it down. If the turbocharger is extremely hot from either heavy load, long drives, or hard driving shutting the car off immediately cuts the flow of oil off and lets whatever oil thats in the turbo CHRA just sit and cook. Then when you go to start the car back up the cooked oil then gets flushed right into the oil pan and collects. After many cycles of this the pick up screen gets clogged and reduces the flow of oil to the entire engine. Bad news bears. Restricted oil flow means more wear and tear, and more contaminates in the oil. All not good for an engine. So to combat this allow the vehicle to cool down. I always let my car cool down a bit depending on how I have been driving. Obviously if the turbo/manifold is glowing from high load or heavy acceleration/abuse it needs longer to cool down. You could sit and wait for this or you could invest in a turbo timer which allows you to key off the car but allow it to still run for X amount of time depending on how hot the exhaust temp is. Regardless this is huge in preventing sludge. I hope this helps!

[9744RR]

I've never used Seafoam in the B6. As long as you don't have any problem with coolant or fuel mixing with the oil then regular oil changes and big oil filter (like the Mobile M301) will prevent sludge. I've been using Rotella for the past 15 years or so and the car burns 0 oil and there is no sludge build up. No cool down time either after regular and spirited driving. And to note the car has been a BT car since 2007. The car is DD and now a DD for my daughter. The car has over 155k miles and climbing.

[Spike00513]

Doesn't the glovebox manual say to not run additives? I suppose whether you do or not is your choice.

I have heard of many methods. Whether this additive or that additive, or using things like ATF or diesel fuel, partially or wholly as oil.
In other words, the crankcase drained of oil, and then instead of adding 4.7qts of oil (or whatever the engine takes), the person might put half or all of that as diesel.
What they do after that? I don't know. Maybe they run it like that a bit, or only crank it over a few times with ignition unplugged (to prevent cylinder combustion), and then let it sit before draining.
Maybe after that they cycle some cheap oil through to flush that out.

However, that begs the question, if the engine is even sludged to begin with.
Supposedly synthetic oil and changes on time is supposed to prevent that, as well as the larger capacity oil filter choice.

However, one potential problem I see (at the minimum), would be the risk of clogging the pickup suction tube screen. That part is kinda cheap.
Whether it gets cleaned or replaced with new; hopefully it does not get clogged with any debris, such as broken up sludge.

Also, I would wonder the effect harsh solvents can have on rubber parts of the engine such as seals.


I'm disappointed that Audi did not put monitoring gauges in the B6, like they did with previous cars, and like other automakers do.
Especially when Audi tries to claim that it's a performance car similar to Porsche and BMW, which probably DO have gauges.

So if hypothetically there were gauges and everything read OK, as well as no signs of abnormal wear, I imagine the engine is fine.
However, I'm no engine expert, and others may know more than me. I don't even know how to use a Plasti-Gauge.

To prevent sludge you have to get to the root of where sludge comes from. Over time oil gets contaminated with coolant, fuel, water, dirt etc so obviously changing the oil at a reasonable interval will help keep things fresh. Next, oil over time breaks down or oxidizes from extreme heat. The little fire breathing turbos on these cars can super heat the oil and accelerate break down and oxidation. So to prevent super heating the oil or "cooking" it you need to keep it flowing and allow the cooling system to do its job. This is all fine and dandy while the vehicle is in motion or running. Where it becomes an issue is when you shut it down. If the turbocharger is extremely hot from either heavy load, long drives, or hard driving shutting the car off immediately cuts the flow of oil off and lets whatever oil thats in the turbo CHRA just sit and cook. Then when you go to start the car back up the cooked oil then gets flushed right into the oil pan and collects. After many cycles of this the pick up screen gets clogged and reduces the flow of oil to the entire engine. Bad news bears. Restricted oil flow means more wear and tear, and more contaminates in the oil. All not good for an engine. So to combat this allow the vehicle to cool down. I always let my car cool down a bit depending on how I have been driving. Obviously if the turbo/manifold is glowing from high load or heavy acceleration/abuse it needs longer to cool down. You could sit and wait for this or you could invest in a turbo timer which allows you to key off the car but allow it to still run for X amount of time depending on how hot the exhaust temp is. Regardless this is huge in preventing sludge. I hope this helps!

I heard Audi/VW figured out a way to keep turbos running for a bit after shut-off, to prevent this. But only on newer cars. Not sure if true.

I've never used Seafoam in the B6. As long as you don't have any problem with coolant or fuel mixing with the oil then regular oil changes and big oil filter (like the Mobile M301) will prevent sludge. I've been using Rotella for the past 15 years or so and the car burns 0 oil and there is no sludge build up. No cool down time either after regular and spirited driving. And to note the car has been a BT car since 2007. The car is DD and now a DD for my daughter. The car has over 155k miles and climbing.

Interesting. I think the phrase is "rode hard and put away wet."
^^I don't have a thermometer on my turbo but either way, I've developed the habit of trying to let the car "relax" for up to a minute after a drive. Sometimes easy for me to do, if I'm pulling into/finding a parking spot after a drive, where the engine is essentially idling. Versus boosting up a hill at high RPM.
But I don't know if it's actually necessary, and sometimes it's tedious.
Same thing for warm-up; I let it idle up to 60 seconds, then drive off and keep RPM's below 2800. Which is slow. I imagine it takes at least 3-5 miles to warm the oil. Because that's what my last rental car showed me on it's oil temp gauge, and it was also a turbo 4cyl.

[Kevin C]

A long time ago I used an oil treatment on a sludged motor. It defiantly loosened the sludge because it all ended up on the pump pickup screen and killed the pump. If a motor does have sludge there is always a risk that you create a bigger problem with the cure. On my 1.8T I have no idea what the crankcase looks like and if I'm on the edge of a partially clogged pick up. I do know that when I did the valve cover the motor looked pretty clean so it seems like a really low risk.

Over 4 years I have just gone with 5000 mile oil changes using synthetic oil. So far so good. I do know that is always that question of should I do something, I have been going with less is more and just change the oil every 5000 and use the big filter. I'm at a 165,000 miles and it all seems good. I think if I was going to do anything I would be to inspect the pump pickup. I don't know if it can be done with a bore scope or not. It sure would be nice to see the pickup without having to drop the pan.

[DPDISXR4Ti]

Thanks for the feedback - good discussion. I do run the big filter and try to stick to 5000-mile synthetic oil changes, so I'm probably fine. I hadn't considered that a more aggressive cleaning might send too much gunk into the oil and clog the pick-up. Too bad the oil pan isn't easily R&R'd. I'd just replace the pick-up proactively.

[PSI NRG]

I heard Audi/VW figured out a way to keep turbos running for a bit after shut-off, to prevent this. But only on newer cars. Not sure if true.

Interesting. I know on some older VW's they have what's called an after run pump which once the ignition is turned off the pump kicks on for a bit, depending on coolant temp, to keep coolant circulating throughout the engine. I'd imagine if it is true it's based off a similar concept. Essentially you just need to keep the fluids moving. So a series of afterrun pumps would all that would be needed. But to keep the turbo spinning I'd think you'd need something pushing air over the turbine or compressor wheel fins with out the presence of exhaust pulses.

[Gin+]

I've learned a few times not to fix something that's not broken.

[old guy]

I've learned a few times not to fix something that's not broken.

In this instance I agree. The 1.8T sludge issue occurred early on with the B6. It affected the 2002 and early 2003 models. Basically it was self induced by Audi. When purchased new Audi performed oil changes for free for the initial warranty period. This oil service was every 10K miles with non-synthetic oil and the small filter. This proved woefully inadequate for the hot little K03 turbo and sludge started forming before the engines were even out of warranty.

In late 2003 Audi made several changes. An additional vacuum line was added to the block ventilation system, a larger filter was utilized and the oil was switched to full synthetic. This pretty much took care of the sludging issue.

If you aren't currently experiencing any oil pressure issues and you have been maintaining a decent OCI utilizing synthetic oil and the larger filter I really don't think you need to be doing anything else.

[Spike00513]

In this instance I agree. The 1.8T sludge issue occurred early on with the B6. It affected the 2002 and early 2003 models. Basically it was self induced by Audi. When purchased new Audi performed oil changes for free for the initial warranty period. This oil service was every 10K miles with non-synthetic oil and the small filter. This proved woefully inadequate for the hot little K03 turbo and sludge started forming before the engines were even out of warranty.

In late 2003 Audi made several changes. An additional vacuum line was added to the block ventilation system, a larger filter was utilized and the oil was switched to full synthetic. This pretty much took care of the sludging issue.

If you aren't currently experiencing any oil pressure issues and you have been maintaining a decent OCI utilizing synthetic oil and the larger filter I really don't think you need to be doing anything else.

The only time I've seen other cars spec high mile OCI's is when they have twice the oil capacity of the 1.8T, and maybe not even a turbo

[old guy]

The only time I've seen other cars spec high mile OCI's is when they have twice the oil capacity of the 1.8T, and maybe not even a turbo

Yep. That's why I recommend a 5K OCI with full synthetics. Best insurance for maintaining a clean engine!

[shurur9]

I have a 3.0 with ~222k
purchased at her supposed "midlife" with 130k.

I run any 5w30 synthetic and dump 1 MMO on the last 1k of a 7K OC,..
Then run KREEN every few OCs

KREEN I says

[IndoReef]

A few weeks ago i ran sea foam intake spray cleaner in my throttle body the entire can
I also added the regular sea foam into my gas tank and oil (did a oil change 500km later)

my car is a early 2002 and personally never had a sludge issue (oil changes every 6k-7k with amsoil synthetic oil)
I was bored and did the sea foam.

Would i do it again looking back...... no it was pointless i got zero white smoke and the car runs just the same, oil was very dirty however.

[Spike00513]

I have a 3.0 with ~222k
purchased at her supposed "midlife" with 130k.

I run any 5w30 synthetic and dump 1 MMO on the last 1k of a 7K OC,..
Then run KREEN every few OCs

KREEN I says

this guy in Germany put 1 million km on his B6.



I've heard of cars getting 1 million miles. Mercedes, Volvo, and other cars.

Granted, his was a 1.9 TDI (diesel) where the whole entire engine block is probably made from strong iron metal instead of aluminum,
but I think so is the 1.8T gasoline engine, and the 3.0L may also have iron cylinder sleeves inside it.
So if the piston is rubbing against strong iron, who cares if that iron is just the cylinder bore sleeve, or the whole block.
If the rest of the block is aluminum (such as the 3.0L), it probably just weighs less, cost less to manufacture, and conducts coolant heat better.

I've seen average people with cars that have 200k+ on the odometer.

A few weeks ago i ran sea foam intake spray cleaner in my throttle body the entire can
I also added the regular sea foam into my gas tank and oil (did a oil change 500km later)

my car is a early 2002 and personally never had a sludge issue (oil changes every 6k-7k with amsoil synthetic oil)
I was bored and did the sea foam.

Would i do it again looking back...... no it was pointless i got zero white smoke and the car runs just the same, oil was very dirty however.

I'm not sure the purpose of seafoam through the throttle body. I'm not judging you; it's cheap and no big deal. I'm just saying in general.
Because in terms of that flowpath on the car, supposedly chemical cleaner products don't work to clean catalytic converters (if that is anyones goal), and IDK if they clean the carbon from the combustion chamber. All that stuff inside, such as carbon coating on the piston tops, and supposedly some inside the piston ring packs.
There's various products that claim to work on that stuff, or even distilled water injection, though I don't know if it's true and never tried it myself.

Once I cleaned pistons on another car but that was by hand using a chemical soak and scraped, because the cylinder head was removed and allowing access.

[DPDISXR4Ti]

Then run KREEN every few OCs
KREEN I says

I've used Kreen before on other engines, but it's a little scary as it seems to thin the oil out a lot, even in small quantities. But it did seem to clean the internals - the oil was as black as black could be! How much did you use and for how long did you run it?

[SleeperAvant]

Very cool video thanks for sharing! FWIW, mine's an '05 with full synthetic oil changes since day one on the big oil filter, utilizing 6,000KM OCI. Current mileage is 280,000kms.

[DPDISXR4Ti]

In late 2003 Audi made several changes. An additional vacuum line was added to the block ventilation system, a larger filter was utilized and the oil was switched to full synthetic. This pretty much took care of the sludging issue.

Good points overall. I suppose I'm just a bit paranoid having witnessed what my neighbor recently did to his late 2003 1.8T, which was a warranty replacement engine. But he was horrible about OCI, so I'm sure that was the primary factor in the engine's demise.

But given that I've now got a bunch of stuff from his car, including a complete 034 PCV hose kit that I put on it ~20K miles ago, I'm considering updating my car to the late 2003+ setup. I recall we discussed this idea before and thought it wasn't worth the spend, but now that it would be a time investment only, I'll reconsider it.

[Charles.waite]

In this instance I agree. The 1.8T sludge issue occurred early on with the B6. It affected the 2002 and early 2003 models. Basically it was self induced by Audi. When purchased new Audi performed oil changes for free for the initial warranty period. This oil service was every 10K miles with non-synthetic oil and the small filter. This proved woefully inadequate for the hot little K03 turbo and sludge started forming before the engines were even out of warranty.

In late 2003 Audi made several changes. An additional vacuum line was added to the block ventilation system, a larger filter was utilized and the oil was switched to full synthetic. This pretty much took care of the sludging issue.

If you aren't currently experiencing any oil pressure issues and you have been maintaining a decent OCI utilizing synthetic oil and the larger filter I really don't think you need to be doing anything else.

Those are the exact reasons Saab NG900s and 9-3s had sludge issues. Saab didn't go to a larger filter but they switched to full synthetic. Solve the issue as it did for Audis.

IMO using additives as regular preventative is pointless if your engine is otherwise running well. Using a good synthetic with a good detergent package really should obviate the need for cleaning additives.

[shurur9]

I've used Kreen before on other engines, but it's a little scary as it seems to thin the oil out a lot, even in small quantities. But it did seem to clean the internals - the oil was as black as black could be! How much did you use and for how long did you run it?

I used half a can and and ran it. Then kept topping it off as it seems to burn off. Then did the OC.

[shurur9]

I used half a can and and ran it. Then kept topping it off as it seems to burn off. Then did the OC.

About the last 500 to 1000 miles...like the mmo