I outdid my tightwad self!

[RJM62]

Fixed the knock sensor on the Subaru a while back. $15 shipped to the door.

Fuel mileage went up 3 MPG, surprisingly. (Measured and confirmed over more than a month of heavy driving.)

When I was driving to the office daily, it would have paid for itself in a little over two weeks, but now it'll take two months before I see the ROI. Heh.

Was showing someone where it's located today and he pointed and said "you have a hole in your air intake hose, you going to fix that?"

Sheesh. I might have to splurge and spend another $10.

This "having a car payment" stuff is horrible. I might have to buy it new tires this fall.

I think knock sensors are probably the part most often replaced simply because they're doing their job. In your case, you replaced the sensor and the code disappeared, so you made the right call. But a lot of people throw a new part at a knock sensor code when the sensor is not the problem.

I had a knock sensor code about a week ago. I suspected either bad gas (because it happened immediately after filling up at a station in the middle of nowhere) or some carbon buildup, or maybe a bit of each. There were no symptoms other than detonation on sustained climbs.

I put some fuel system cleaner in the tank and drove it hard up a few of my favorite hills, holding back a bit on shifting to keep the revs in the 3,500 to 4,500 RPM neighborhood under load. (I usually shift at 2,200 to 3,000 RPM, depending on load.) The light went out after a few trips, but the code stayed "pending" for about a week. So I ran the tank down to almost empty, filled up with good gas, cleared the code, did a couple of textbook drive cycles to ready all the OBD2 subsystems, and have been driving normally since then. The code hasn't returned.

I've also refilled again since then, and so far on this tank I'm 2 MPG above average. That's within the normal deviation so it's hard to say whether it means anything; but it's possible that the hard driving blew some schmutz out of the system and resulted in some fuel savings. Cars that are usually driven gingerly often benefit from being driven hard once in a while.

As for tires, I use Discount Tire Direct. If you time it right and use their ****ty Synchrony credit card (or any other CarCare One card), you can get incredible rebates. The savings are so good that I keep a CarCare One card alive by using it at Exxon or Mobil stations every few months just so I can get the tire savings at DTC. (Just make sure to pay it off well within the interest-free period, otherwise Synchrony will hit you with Shylock interest from the date of purchase. I just PIF on receipt.)


Rich

 

[frfly172]

Good job.,taking you might have gone a little high on the mower.

 

[denverpilot]

I think knock sensors are probably the part most often replaced simply because they're doing their job. In your case, you replaced the sensor and the code disappeared, so you made the right call. But a lot of people throw a new part at a knock sensor code when the sensor is not the problem.

Probably true. In my case, the knock sensor itself failing is a known problem with Subaru knock sensors. They're junk, thus the $15 price tag. Ha.

I wasn't just working off of thinking it was toast, I knew it was.

Wasn't any knocking going on in that old four banger...

Subaru sends gobs of fuel through the engine at idle if it thinks it's knocking. Which interestingly means that you can smell that the knock sensor is dead on an old Subaru, from nearly gagging on the fumes on a cold start. Ha. I joked with Karen that I could probably install a spark plug in the tailpipe and have a little afterburner assist back there.

There's a test procedure for the thing, if you're really bored, but it clear it was dead.

 

[GeorgeC]

...
I put some fuel system cleaner in the tank and drove it hard up a few of my favorite hills, holding back a bit on shifting to keep the revs in the 3,500 to 4,500 RPM neighborhood under load. (I usually shift at 2,200 to 3,000 RPM, depending on load.)
...

What sayeth PoA on the various products that purport to clean the induction system/intake valves/etc? Preventative maintenance, placebo, or snake oil?

 

[denverpilot]

What sayeth PoA on the various products that purport to clean the induction system/intake valves/etc? Preventative maintenance, placebo, or snake oil?

Depends on whether the design of the engine was faulty to begin with. A well designed engine won't have such problems.

There's quite a bit of video evidence of problems with specific Ford EcoBoost engine intake manifolds from highly qualified (Ford trained) techs who own them personally and have enough standing with Ford to argue inside the company about it, for example.

I've stumbled across them on YouTube, and they're professionally done, and the internal responses to Ford techs who own them is pretty poor.

Ford engineering still says says using such cleaning products will destroy the turbos, but has quietly paid for a number of engine tear downs under warranty to essentially do what we aviators would call a top-overhaul, when borescope video from their own techs show the valves are trashed with carbon.

The cause is the emissions garbage. The cylinders affected are always the two closest to the EGR port on the intake manifold.

I'm not picking on Ford, all manufacturers have this stuff. It's just a modern example.

Dodge has no fix for the never ending steering problems on their heavy duty trucks, either. The solution is simply to rebuild the entire steering system from the track bar out, every so often. It's known as the "death wobble" for a reason, it's probably hurt or killed people.

VW forums are loaded with posts on how to rotor rooter out the crap the emissions system creates in their exhaust manifolds on their diesels.

It really is worth spending some time reading brand specific online forums before purchasing vehicles, because the real problems will come up again and again and again. If you find repetitive posts where people feel a need to clean intake manifolds and injectors all the time, something is wrong with the design.

So there's no easy answer to your "snake oil" question. Some engines with bad designs may benefit from such a "cleaning", but it's a cover-up for a different problem. Good gas and air don't clog up intakes, and burnt exhaust doesn't either. Most of these problems can be traced back to trying to return gunk through the engines that never should have been returned.

In the case of the Fords, the correct solution is simply to remove the EGR system that pipes oily dirty crap into the intake manifold where such crap was never intended to be, but you'll create yourself a warranty hassle as well as be in violation of various laws, and if done wrong, the vehicle's computer will know and snitch on you -- all for removing a real problem so your engine will not need to be taken apart every so often and rebuilt.

The techs all hope Ford will come out with some magical filter to put on the EGR system. I doubt they will. Numbers say it'll be cheaper to wait and see how many are out of warranty prior to becoming so bad they trigger a misfire. Only have to pay for the ones under warranty.

That's how the problem was found, after all... Techs troubleshooting misfire codes on their own vehicles and couldn't find reasonable souutions that work, so they stuck cameras in their own engines to see WTF was going on, and knowing there was no engineering approved cleaning procedure, and having seen owners do their own cleanings and trash the very expensive turbos.

 

[GeorgeC]

All I know is 1) the dealer recommended their fuel induction service after my 60k scheduled maint, and 2) I can run a can of PEA detergent through the intake for less than the $200 they were asking. They claimed they observed carbon buildup, but I haven't borescoped anything personally. Car drives fine and gets its usual mileage. No CEL so I haven't plugged in my code reader.

 

[RJM62]

What sayeth PoA on the various products that purport to clean the induction system/intake valves/etc? Preventative maintenance, placebo, or snake oil?

Some of them do something. Some not so much. And the ones that do something don't necessarily do more good than harm.

Amsoil P.i., Redline SL-1, Techron, and probably others use PEA as the primary active ingredient. My experience is that they do help some if a car's suffering from the problems the products are designed to cure.

Kia recommends Techron every so often (I think 7,500 miles, but I wouldn't swear to it) if TopTier gas isn't available where the car is used (which would include Sparrow-Fart, New York). I personally prefer Redline's products, however, so that's what I used this time around.

More regularly, I use the marine flavor of STA-BIL at 1 oz / 10 gallons at every fill-up. I've had a few problems with gas going stale in the tank in the past. I haven't had those problems since I started using STA-BIL.

You have to understand that where I live, all the gas stations are low-volume except from June through August, so the gas isn't all that fresh when you pump it. The STA-BIL seems to at least prevent it from getting any worse before I burn it. When I get bad gas, I know immediately. The occasional bad tank of gas part of life up here. But if it's not bad when I buy it, the STA-BIL prevents it from going bad before I use it.

I also use STA-BIL in the ethanol-free gas I buy for all the power equipment. It seems to keep it fresh for about a year at 1 oz / 5 gallons. I don't use it in the ethanol-free gas that I buy for the ultralight's Kawasaki engine because I usually burn that gas the same day I buy it. If I don't, then I either give what's left away, or I add a dash of STA-BIL to it and pour it into the gas can for the chainsaw (which also uses a 40:1 gas/oil ratio).

Another additive that I've used a few time in clogged cat situations on older cars is Cata-Clean. I'm pretty sure it's lacquer thinner (which I also used back in the day), to tell you the truth. It burns all the **** out of the combustion chamber, exhaust system, and cat. Quite often, it really will clear up a P0420 / P0430 code. That's the good part. The bad part is that in my experience, it also tends to blow holes through an older car's exhaust system (except, ironically, for the cat, presumably because it's designed to handle higher temperatures).

I've also used piston cleaner on various Saturns that I've owned. When I couldn't get piston cleaner, I've used MMO, SeaFoam, ATF, or other miracle cures that were popular at the times. It was a several-day process that involved pouring the cleaner into the cylinders and letting the pistons soak in it. The need for piston soaks was a common situation with old Saturn engines. The oil couldn't drain because of a lack of drainback holes in the pistons. Over time, the oil formed carbon deposits, and piston soaks were the easiest way to clear it out.

I suppose the Cata-Clean would also fix the Saturn carbon problems, but I haven't owned a Saturn in a while. If I ever buy another, maybe I'll give it a shot instead of the piston soaks. The Saturn's exhaust systems were pretty tough -- I never replaced a single part of a Saturn exhaust system other than an occasional hanger -- so it probably wouldn't burn through them.

As for the other additives, meh. I think most of them are probably useless, but also harmless. Others are useful in some specific cases (like the STA-BIL in my situation or the piston soaks on old Saturn engines).

Rich

 

[stratobee]

I've found that tightwads are normally in the hoarding camp as well. They'll collect stuff just because it was free or a good deal, regardless of if they actually need it or not. Come home to them and they've saved every jar since 1969. They have to have storage and buy bigger houses for all their accrued cr*p. And their yards look like something out of Texas Chainsaw Massacre. So in the end, it'd probably be cheaper to buy the more expensive thing that's better quality, than sit on 20 half eaten mowers from China and 500 free T-shirts with stains "that you can wear around the house"...

 

[RJM62]

I've found that tightwads are normally in the hoarding camp as well. They'll collect stuff just because it was free or a good deal, regardless of if they actually need it or not. Come home to them and they've saved every jar since 1969. They have to have storage and buy bigger houses for all their accrued cr*p. And their yards look like something out of Texas Chainsaw Massacre. So in the end, it'd probably be cheaper to buy the more expensive thing that's better quality, than sit on 20 half eaten mowers from China and 500 free T-shirts with stains "that you can wear around the house"...

That's not true of tightwads who were raised in New York City. We never had enough space to be hoarders.

Rich

 

[RJM62]

I think it was time...



Rich

 

[Clark1961]

I think it was time...

Coulda been wrapped in aluminum foil and been fine another season...

 

[rbridges]

I think you could have done better
I see grills free all the time on craigslist. Plus free non working mowers.
We expect better next time

The mooney website has a cheap bastard group. The OP came close to qualifying.