Problems After Dealership Oil Change - Any Ideas?

[Picasso]

I discovered the primary cause of my engine issues. The fuel filter was clogged. (Insert primal scream.)

Replaced it three days ago and almost all of the harshness and exhaust noise problems are gone. Engine responsiveness is noticeably improved even in neutral. Accelerating on the highway is quicker. My truck is back to being a very comfortable road cruiser.

There is still a slight vibration with the engine while revving it at 2000rpm but it is greatly reduced. I wonder if this indicates a partially clogged injector that was exacerbated by the lower fuel rail pressure that existed with the clogged fuel filter.

Looking back, I think I can piece together the symptoms and their causes. Prior to the dealership oil change, I thought I had gotten bad gas on a number of occasions because immediately after fill ups, my truck would run noticeably better. My engine also started to ping during this time frame. Must have been bad gas from the previous station, right? What I think happened was that every time I filled up my tank, which is almost always empty when I fill up, I relieved the vacuum in the tank that is created as the fuel is depleted. When this happens the fuel pump has that much more pressure to push fuel through the clogged filter and my truck suddenly runs better.

Given that, I cannot associate the dealership oil change to my engine problems. I must have been at or lower than half a tank the day I had the oil change.

I got the donut gasket fixed finally and no more hissing from it. Very smooth now.

I can tell that my ECU is adjusting to all of this as my truck is performing better every time I start it up. What a relief. I guess I won't be taking it to the crusher after all.

There is still some vibration in the truck at around 70 mph but it is strangely reduced. Supports my theory that the Tundra's suspension and drive train are inherently unstable and will vibrate sympathetically whenever any vibration is introduced by anything on the truck. Hope Toyota was able to resolve that for the 2007 design.

Blackstone Labs oil analysis report for my truck showed that all wear metals were below the universal averages with the exception of silicon which was at 15ppm versus the universal average of 14ppm. There was a trace of fuel in the oil at 0.5% which was still below their recommended value of 2.0%. Don't know if that's significant or not.

I'll post my experience with changing the fuel filter in another thread. It was not too difficult but it was also not straight forward.


Paul

[mustang67408]

gLAD TO HEAR YOUR tUNDRA IS BACK TO RUNING PROPERLY and its not going to the crusher.

A fuel filter? WOW, thats a first for me.
Also glad to hear it wasn't the dealerships fault.

[Picasso]

Originally Posted by mustang67408

A fuel filter? WOW, thats a first for me.

Yeah. Ain't that somethin.

In my research to try to find more clues to diagnose my symptoms, three things kept coming up consistently as a possible cause:

1. O2 sensor
2. Ignition
3. Fuel pressure (be it from the fuel pump, regulator, and maybe fuel filter)

The O2 sensor was mentioned the most with the fuel filter being mentioned the least number of times. The fuel filter wasn't mentioned so much as it was hinted at. Most references to the fuel filter involved it cutting off fuel flow entirely.

Since I still had the original fuel filter on my truck, with 77k miles on the odo, I decided to replace it. I could literally breath through the new filter but could barely get any air through the old one when I tested it after its removal. I would guess that the old filter had about 15% of the flow capacity of the new one.

I know that many people on this forum have mentioned that the fuel filter should be replaced at 60k miles and my Haynes manual also lists this as 60k mile maintenance item. Strangely, I cannot find the term "Fuel Filter" anywhere in my Toyota Maintenance Guide. As a result, I have never given it much thought as a maintenance item.

Live and learn.


Paul

[mustang67408]

Toyota has NOT recommended changing the fuel filter since they started injecting veicles and the carbs went away(90's). We used to sell them at 30k, 60k & 90k miles, but people kept complaining. "IT's NOT IN MY MANUAL, YOUR TRYING TO RIP ME OFF AND SELL ME SOMETHING I DON'T NEED"."SHOW ME WHERE TOYOTA RECCOMENDS IT".
So we stopped trying to sell them. It is a good maintanace item to change at your major service intervals (IMO).

[Picasso]

Just an update to the status of my truck.

When I replaced the fuel filter, the engine improved to about 80% from how it performed prior to the symptoms appearing. When I put the fuel injectors back in after getting them refurbed, I hoped that the engine would be back to 100% but this was not the case. The problems actually seemed to be a little worse immediately following their install.

Here's the strange part.
Recently, the symptoms have suddenly begun to decrease. During the injector removal process I disconnected the battery, clearing the ECU trim tables. During the relearning process, there was no change in the symptoms. I've put well over 2k miles on my truck since reinstalling the injectors and only now am I getting improvements.

My truck performs at about 90% from what it was before the symptoms started. The sound of the exhaust is still louder than before and my truck still shakes while driving at highway speeds due to the engine vibration. The engine still shakes a little when revved in neutral, just at different RPMs from before. Previously the engine vibration peaked at 2000 rpm. After the injectors were refurbed, the vibes peak at 1700 and 2300 RPMs. The torque is good but I think it should be better.

I bought a fuel pressure gauge to check the fuel pump but nothing conclusive came of that. I got 45psi while idling in Park. With the gauge connected I did I test drive and the pressure only dropped to about 42 psi when I accelerated to 50mph. The gauge dial indicator shook rapidly ± 2 psi while centered at 42 psi during hard acceleration but was perfectly still while idling. Don't know what this indicates if anything.

I'm still confident that the main problem is the air/fuel mixture and I suspect a lean condition. The sound of my exhaust and the engine suggest that one cylinder is combusting differently from the others.

RECAP
With the exception of the slight pinging, the symptoms appeared overnight and are now starting to decrease for no apparent reason. If I could determine what would act like this it would help me find the problem. At this point I don't know.

I'm going to swap the injectors (left rail with right rail) without disconnecting the battery to see if there are any changes. If so, this would indicate an injector issue. Another reason I'm going to do this is that when I reinstalled them, I put them back to maximize their balance (as measured by the injector refurb shop) with the engine firing order. The problem is that I used the diagram in the Haynes manual which has the banks reversed for the V8. Don't know why I hadn't noticed this before. The V6 diagram is correct. I doubt that the injector balance is an issue but the swap is a good test at this point.

I might try swapping the coil packs before doing the injectors, since that would be very easy. I really don't think the coil packs are an issue but I could cross them off the list of possibles.

I'll post any updates.


Paul

[mustang67408]

The V8 engine

Cylinders 1/3/5/7 are on the drivers side

Cylinder 2/4/6/8 are on the passenger side

This is opposite of the V6

[Picasso]

Originally Posted by mustang67408

The V8 engine

Cylinders 1/3/5/7 are on the drivers side

Cylinder 2/4/6/8 are on the passenger side

This is opposite of the V6

The Haynes shows the odd numbered cylinders on the passenger side for both engines.

[mustang67408]

Originally Posted by Picasso

The Haynes shows the odd numbered cylinders on the passenger side for both engines.

Good Thing we use Toyota manuals.

[SWSportsman]

Picasso, I just have to ask: Why would someone as obviously skilled and knowledgable as you are take your truck to a dealer, especially for an oil change?

I hesitate to even drive down the highway where the Toyota dealership is located.

[Picasso]

Originally Posted by SWSportsman

Picasso, I just have to ask: Why would someone as obviously skilled and knowledgable as you are take your truck to a dealer, especially for an oil change?

I hesitate to even drive down the highway where the Toyota dealership is located.

I know what you're saying and I feel the same.

The reason was that I was leaving on a long road trip and I had gone longer on the oil than I wanted. The garage where I usually change my own oil, had closed early three days before. The dealership was one of my last options before the trip.


Paul

[Picasso]

Just an update to this saga which unfortunately HAS YET NOT ENDED.

I'm getting very close to resolving all of the symptoms that I mention in this thread. Replacing the PCV valve grommet helped significantly as mentioned in this thread and replacing one of the coil packs as mentioned in this thread was an enormous improvement.

I think my truck's engine is back to 96% and my truck as a whole is at about 90%. Has all of this been a coincidence or did the dealership do something fishy to my truck when I brought it in for the oil change?

This has been going on so long that I'm beginning to feel like Ferris Bueller's friend Cameron on the morning that Ferris calls him and tries to get him to drive over to Ferris's house. I can at least say that I'm making progress and today was an especially good day in that regard.


Paul

[urbankummerer]

First time on this site. I have a 2000 v6 SR5 manual tundra. Check engine light came on and got a low efficency catalytic converter front. Since then I have had the same shaking as you have described specifically after shifting into 5th and get up to 65-70mph. Called the Goodyear I normally take our vehicles to and they quoted the part at $1690.00 total job would be $2000. I thought they had too many zero's. Just wanted to know if this made a large improvement for you and after looking online it looks like there are two catalytic converters on my model a front and side. The front looks like it should cost around $275. Just wanting some advice before I try calling other garages for quotes.

[LifeTech]

Originally Posted by SWSportsman

Picasso, I just have to ask: Why would someone as obviously skilled and knowledgable as you are take your truck to a dealer, especially for an oil change?

I hesitate to even drive down the highway where the Toyota dealership is located.

My Toy gets the shakes and anxiety attacks if I just drive by the Dealer.

But the I give her reassurance and she's happy again, when I speed away from that dealer.

[Picasso]

After replacing all 8 ignition coils, I was hoping that my engine problems would disappear. No such luck.

Most of the engine shaking is gone but is still significant at highway speeds. The engine feels like there is uneven compression between the cylinders and I've still got that sound like one of the cylinders is firing differently. I've checked vacuum, compression, MAF, had the injectors cleaned, and replaced the plugs, coils, fuel filter and air filter.

The only obvious problem that my truck has is the CEL is on for low catalyst efficiency bank 2. This is the same cat that I recently had to replace. The welding job done by the muffler shop wasn't great, and there was a pinhole leak which initially caused the CEL. When I got the pinhole welded, the CEL went out but returned a couple months later. Is this related to my engine problems? Maybe. I swapped all 4 O2 sensors from one bank to the other. The trouble code did not follow the sensors. I'm going to do the same with the injectors to eliminate them as a possibility. It could also just be that the gaskets that are on each end of the cat are leaking. I've had to deal with that before. Amazing how sensitive the O2 sensors can be to a leaking gasket.

I'm going to do a little more investigating with my scan tool. If nothing comes of that, it looks like I'll be pulling the heads when the timing belt gets replaced. The thing about the heads is that both vacuum and compression checks didn't indicate any problems. I'll check them again for good measure.


Paul

[cupidstoy]

couple of things i didn't see mentioned.

did you check the motor mounts? a loose or cracked motor mount could be a possible source of vibration.

you said your exhaust still sounds louder. any chance the muffler shop ripped you off and put a used or bogus (or non at all) catalyst in your cat location on the side they replaced? that might cause the type of left/right bank imbalance that could introduce vibration and would also account for a different exhaust note and the CEL.

just some thoughts. sorry your having trouble.

cupidstoy