98GS300-2

Hey guys, I'm new to the Lexus/Toyota side of the car scene so I'm still in the dark as to what my car can and can't take and how much I have to worry over certain issues...

That being said...I washed the engine bay on my GS300 yesterday, no high pressure water or anything just a light dribbling over everything so I wouldn't get electronic parts too wet or anything. After doing that I took it for a quick spin just to help the drying process...that drive went fine.

Later last night I was going to head over to a buddies house and was going to take the GS. Got about 2 blocks down the road and it felt like it was missing pretty bad...it would sputter/shake/buck pretty decently so I turned around, parked it, and took the mustang instead. Thinking some water probably just got into somewhere it shouldn't have I was hoping it would evaporate overnight and be good to go today...no such luck. I took it out with my dad to have him check it out and it was driving fine until about 5 min into the drive when it started bucking and shaking again. Now whenever I even turn the car on it shakes pretty bad.

I'm thinking I probably just got water into something with the spark plugs and maybe fouled a plug or something but with the process of checking/replacing plugs being more involved on the GS than I'm used to I'm hoping to get some 2nd opinions to make sure I'm thinking correctly! Do you guys believe it's the plugs/coil packs or what else could possibly be causing it to do this? The car is now sitting out in my driveway with the sun beating down on the engine to hopefully help bake anything else away. Thanks and sorry for the long post.

Quick car info:
1998 Lexus GS300
158,000 miles

phillygs3

iTrader: (5)

Never wet your engine I wipe my engine down with a rag I never put water near my engine

handoverfi

iTrader: (7)

that is what i wanted to know also!! but wiping it down sounds good! any kinda special cleaner you use?

phillygs3

iTrader: (5)

simple green sprayed on the rag , then some tire dressing to shine the plastic

98GS300-2

Yeah I suppose I should have erred on the side of caution and just wiped it down but I'm so used to the mustang just taking it like a champ I figured the GS would handle it even better. So are you thinking I'll probably just need to change plugs or could it be something worse?

phillygs3

iTrader: (5)

try some compressed air blow everything out real good and take your spark plug wires off and let them air dry

98GS300-2

I let it sit and idle and finally got P0300, P0303, P0305...

300 - Random misfire
303 - Cylinder 3 misfire
305 - Cylinder 5 misfire

Tonight I'll pull it apart and check it out...if anything looks off I'll clean it and see if that helps. If not I'll start doing some replacing! Chalk it up to a learning lesson for me I guess...hopefully it's not too costly since I just paid my tuition bill today too :/

Philly: I sprayed it down with the air compressor today for about 5 min and it's been sitting in direct 85 degree sunlight for about 3 hours too. It's still doing it so I think it's going to require me to do some digging. At least I get to learn what the engine looks like now. My car and I get some unscheduled bonding time.

phillygs3

iTrader: (5)

looks like spark plug 3 and 5 mite need to be dried out or replaced good thing you didnt ruin any sensors

jonny2k

My buddy is a former Lexus mechanic and one of the first things he told me after I bought my GS was to avoid steam cleaning or washing out the engine bay. He told me to just wipe things down on a regular basis using damp rags and it should keep it relatively clean. The area that he said water tends to pool up is a channel around the intake manifold, which is usually under that plastic engine cover. If you have access to compressed air you may want to try and blow out any moisture around the intake manifold.

Other than that, next time use compressed air and a rag soaked in Simple Green just as someone else recommended.

Good luck!

98GS300-2

Thanks for the help guys! One last question that I'm having some trouble finding an answer too...what is the cylinder layout on the car? I wish it was as easy as 1-6 front to back but I have a feeling it's not! Thanks again!

phillygs3

iTrader: (5)

This should help

98GS300-2

Well we pulled all the packs/wires/everything BUT the plugs out(figured no water/coolant could get down there and if it did it would burn off and not cause continual missing), cleaned them off, sprayed compressed air, vacuumed, double cleaned, and reassembled everything. Started it up...seemed good. Backed down the driveway and thought I felt or heard it miss, shifted into drive and started pulling forward, started missing and shaking again. Crap...

98GS300-2

So should I just buy new plugs and hope that solves it or is there something else I'm missing that could have been damaged in the process? I just don't see how a little moisture on the plugs could ruin them...it should evaporate right off when you turn the car on I'd think. Maybe cause a few quick misfires then evaporate out and run like a charm.

PHML

iTrader: (33)

I've been washing down my engine bay for years....nothing has ever happened like what your are describing.

What I do is make sure to keep the air intake dry.....Simple Green everything...even electrical sockets.....then start the engine.....keep it running while watering it down....then blast compressed air while engine is still running.

You may want to keep the hood up and let it dry during the day....if you have a compressor....try blasting away.

98GS300-2

No such luck!

It has sat out for 2 completely sunny 80+ degree days, has been taken apart down to the plugs (plugs not removed) and vacuumed and blown for quite some time with compressed air. Still misfiring...so now I'm wondering what electrical component I FUBAR'd...