Carbon build-up and Redline?


The car dealer mechanic tells me I need to replace my fuel pump and injector due to “carbon build-up”… I only have 40,000 miles on my 2004 Toyota Highlander 4WD 4-cylinder, but the guy at the dealer told me that it had to be replaced every 30,000 miles and was not under warranty or normal maintenance. So he told me I’d already gotten an extra 10,000 miles out of it, but that doesn’t make sense cause my parents have not had to do this for their Highlander which has 80,000 (a 2003)… He quoted me $160 for the the injection system and $120 for the pump replacement (and that fixing one and not the other was not an option), but I don’t know if that even included mechanic time or just the parts…

I generally get gas at Shell and sometimes Hess, however on occasion I have gotten it at Crown (but not that often and most Crown’s are now becoming Texaco). So perhaps that’s why, and I should just stick to Shell? Like is carbon build-up a result of bad gas?

It just seems weird when the car isn’t even 4 years old yet (2004).

Do you know if this is a common problem?

A friend recommended using “Redline” that I can buy at an autoparts store.



Clarification would help. Are you sure you don’t mean fuel FILTER instead of PUMP?
No way you’re going to get a pump for 120 bucks.

Some of it sounds like BS. Neither the pump nor the filter would have anything to do with carbon buildup.
If the vehicle appears to be running fine skip this.
I am of the opinion the fuel FILTER is past due for replacement though.

Considering some of what you’ve been told and nothing has been lost in the translation, I would get someone else to change the fuel filter.


My first question is: is there anything wrong with your car?

The fuel pump is NOT a maintainance item, nor does it become plugged with carbon. If your car is running fine, don’t worry about it. If not, I’d say take it somwhere else. It sounds to me like a classic case of shiestery mechanics trying to talk over your head and, besides, there is no reason to take your car to the dealership once you are out of warranty. The serivce is no better than a good independant shop and signifigantly more expensive.

What could be happening is your fuel filter may need to be changed, which if neglected long enough, could take the fuel pump with it. However, most newer cars have fuel filter change intervals that most on this board find ridicuously long-- things along the order of 100,000 miles or even never. Consult your owner’s manual for the recommendation for your vehicle.

There is almost no difference between the brands of gasoline. It all generally comes from the same refinery with only subtle additive differences, none of which (despite their commercials) will make a bit of difference to the long-term health of your car.

There are various fuel injector cleaners on the market that you add to your gas tank. It may be a good idea to add a bottle to a tank every few thousand miles on an older car to keep the injectors clean, but I think your car is still way to new to need it.

Post back with your specific symptoms or otherwise don’t worry about it, I’d say. And find a good independant mechanic.


Thanks, I got the distinct feeling the guy was trying to pull one over on me, but I don’t know anything about cars…
Anyways, I had an oil change and right after the check engine light came on, I took it back and they said the air/fuel sensor had failed and was under warranty still so they were going to replace it but ALSO that due to carbon buildup I had various ‘other’ fuel injection problems (I have nothing in writing to refer to though)…he rattled off the price of each fix and said it was ‘suggested’ to be done every 30,000 miles, but I had had them do the 30,000 mile check up and they didn’t fix it then since its not ‘routine’.

Sorry if I’m not using the correct terms, I really am trying to remember what all he said. I think my car is ok overall, just hesitates occasionally at accelaration…which is why a friend recommended the ‘redline’.


I have seen enough. I will never buy a Toyota if they allow crooks as per your description to run free with your inexperience and your money. That is scary, to think that the Toyota dealer’s people might cheat you if you don’t know cars.


If your car appears to run fine then don’t worry about injector cleaning, additives, induction system cleaning, and other garbage like that.

There may come a time when it is needed (150k miles maybe), but not at this point.
If an injector ever acts up or the induction system is clogged enough to worry about you will get a Check Engine Light or you may notice a very slight miss at idle that smoothes out when you accelerate.


As far as I know, Redline is an expensive synthetic oil. It might help your bearings and rings last linger, but it wont do anything for your injectors or for carbon build up, of which I doubt that you have either. I thing this service writer (not mechanic) is trying to get into your wallet.

You should talk with the manager at the dealer and let them know you are very uncomfortable with what this person is telling you. If the manager tries to stick up for the service writer, then find a good independent mechanic in your area.


Find a trusty independent.

There is no way in any modern car that anyone can replace a fuel pump for $120 including part/labor.

Follow your manual and if an issue occurs take it in for warranty work only to these jokers. If they complain call the Toyota help line.


Why blame Toyota? All dealers do this. Look in your owner’s manual, and do ONLY what is required there. this dealer is dishonest.


To be fair, it sounds to me like the OP is having some fuel system issues and that the price quoted to fix it seems reasonable, I just think the service writer is being lazy and isn’t actually explaining what the problem really is, instead just giving a stream of technobabble. Maybe he even doesn’t understand it himself-- I’d believe this with some service writers I know. It’s not good customer service, but I’m not sure they’re necessarilly being dishonest.

I know sometimes when I’m dealing with a complicated problem in a hectic situation, I’ve been known to tell a customer something that’s a marginally inaccurate over-simplification just because I don’t really have time to give a complete explaination of what’s wrong. I fix restaurant eqipment professionally, btw, not cars.