I've got a 2008 Lexus IS250 and I'm about to dig into the top of the motor and do a walnut blast carbon cleaning of the valves and valve chambers. I bought the car with 185k miles on it, it now has 220k miles. I'm definitely going to change the spark plugs and the PCV valve while I've got the intake cowl off. Should I just go ahead and change the ignition coils at the same time? I'm not getting any codes or misfires or anything, but I doubt they've been replaced in a long time. What do you think?
Personally, if the "ain't broke, don't fix it" moniker stands, don't fix it if it's not causing problems. I have a coil pack I believe is the original coil pack from Ford in a 1999 Ranger. They're obviously not the same make, nor model car, but Lexus is built better than Ford.
I forgot to mention, the Ranger has 291k miles on it.
If they are easy to replace, wait until you get signs. If they are hard to replace, like you need to remove a bunch of unrelated stuff to get to them, might be a good idea to consider replacing, depending on the cost of them.
im curious to see before and after pictures of the valves if you don’t mind sharing when you get them done.
Whoa! That’s pretty cool. Looks real good now!
I would leave them alone if it’s not causing issues (and you are currently not getting any misfires). If they are relatively easy to remove and install, then even more reason to let them be until it’s absolutely needed.
I'm about to dig into the top of the motor and do a walnut blast carbon cleaning of the valves and valve chambers.
why? did you inspect with a boroscope to see if there's anything there? Toyota has port injection so there shouldn't be.
I'm definitely going to change the spark plugs
why? Is it running poorly? Again, inspect them and see if it's even needed. You've owned it for 40k , and those things can last more than 100k.
Should I just go ahead and change the ignition coils at the same time?
nope. When they're bad, you'll know. Otherwise they could last the whole life of the vehicle.
The IS250 is one of the rare Lexus vehicles that has a direct injection only engine.
Aha. Forget what I said about port injection then.
It definitely needed the walnut blasting, and the plugs The symptoms that prompted me to do this laborious procedure, knowing it was a direct injection motor, were a very rich smell at start up, sluggishness at the low end of the power curve, and just a general vibe that the car had been not diligently cared for over the years. Not abused, I think it did a lot of highway miles, but not owned by someone who was overly interested. It never got it's sticky dash fixed even though there was a recall until 2017, for instance.. Oh, also and most noticably, the gas mileage was pretty poor and had gotten worse. Turns out the valves and chambers were in fact pretty called in carbon I just got this knocked out tonight and I can tell a big difference in the power, more than a placebo. I'm going to give it a few days to see the difference in MPG, then I'm going to add the ATS fuel system cleaer, see if that compounds any mileage gains. The oil isn't due for a change for almost 4k miles, but I'm probably going to do it sooner along with the ATS oil cleaner done before the change. I'm gonna post the pics in this thread if you are interested.
always interested
Thanks for the input, y'all. I think I'm going to hold off on the coils, order the ATS fuel system and oil system cleaners with some of the money I save. On a bit of a quest to get better gas mileage. I will post pictures, before and after, of the valve chambers when I do the walnut blasting, Saturday the 6th of Sept.