Hello all,
I recently put my 94 Q45 in for service, and I asked the mechanics to give me a ball park of estimated useful life – I already have 90k on the car. Their response was something I wasn’t expecting. They said that, in all 94 Q45s, there is an abnormal buildup on the exhaust valves which at best requires a cleaning through the exhaust manifold ports or at worst requires a valve job. Can anyone confirm this as either fact or fiction? If its fact, what’s the best way to prevent the problem? What’s the cure for the problem? Is this really a design problem that all 94 Q45’s must someday face?
What do the Tech’s who regularly work on 94 Q’s say – is my mechanic right?!!
Thanks,
Stephen
Rumor of Valve Problems on 94Q?
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Owners who don't excerise the engine [and do a lot of low speed traffic] without the weekly high [rpm] speed runs can build up deposits on the valves of any engine.
Usually the BG44k treatments take care of the problem.....lots of it has to do with the available gasoline.Why I use it prior to every oil change [every 90 days]!
Just do a few WOT runs getting up to 70 mph and a few WOT 50-80 mph passes each week and the stuff will blow out in a big cloud of black smoke.
Gotta keep the plenum clean of EGR crud which eventually adds to the problem.
We have many 94,95 Q customers with over 150,000-180,000 miles and 2 with over 230,000 miles.But then Atlanta drivers are known for high speed operation.......80-90 mph [55 mph unenforced speed limit] is the norm on our loop expressways.
As the average speed has gone up fewer accidents per car mile driven.......more focused.........but when they occur they are dozzies........SUV's are fun to watch as they flip in lane changes at these speeds..........we all cheer with glee as the cellphone flies out the window first in mid air!
Usually the BG44k treatments take care of the problem.....lots of it has to do with the available gasoline.Why I use it prior to every oil change [every 90 days]!
Just do a few WOT runs getting up to 70 mph and a few WOT 50-80 mph passes each week and the stuff will blow out in a big cloud of black smoke.
Gotta keep the plenum clean of EGR crud which eventually adds to the problem.
We have many 94,95 Q customers with over 150,000-180,000 miles and 2 with over 230,000 miles.But then Atlanta drivers are known for high speed operation.......80-90 mph [55 mph unenforced speed limit] is the norm on our loop expressways.
As the average speed has gone up fewer accidents per car mile driven.......more focused.........but when they occur they are dozzies........SUV's are fun to watch as they flip in lane changes at these speeds..........we all cheer with glee as the cellphone flies out the window first in mid air!
It's probably going to get more dangerous in the coming years as SUV's begin to comprise a larger and larger perentage of used car inventories on the lots. Vehicles with high centers of gravity on worn out suspensions due to age and oversized bling bling rims on worse and worse tires being driven by inexperienced, younger, aggressive drivers talking on cell phones will certainly bring the accident per mile statistic back up again. Air pollution levels should begin to creep up again, too, not to mention keeping the money flowing to the middle east for years to come. :rolleyes
-
Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Actually it takes 57 ODB2 compliant cars to equal one pre 1990 in good condition. OBD2 are about 3 times better than 1990 OBDI is less total pollution
Getting EVERY pre 1990 off the road should be JOB #1 or at least set the annual tag prices at $5,700 per year for collectors.
The EPA goal is to never have any car older than 10 years on the road...........
The problem is poor people who must drive but can't afford to keep in spec.
California did a $750-$1,000 buy back and crush with a grant [polution trade] from power companies.
Getting EVERY pre 1990 off the road should be JOB #1 or at least set the annual tag prices at $5,700 per year for collectors.
The EPA goal is to never have any car older than 10 years on the road...........
The problem is poor people who must drive but can't afford to keep in spec.
California did a $750-$1,000 buy back and crush with a grant [polution trade] from power companies.
Thanks Q45 Tech.
I don't have a problem with the Q right now, (fortunately) but I was more concerned that there is something in the design of the exhaust valves which causes abnormal build up.
It looks like we will be keeping the car for another 3-5 years, so I plan on doing the following myself:
Plenum cleaningTB cleaningSpark Plugs (platium)knock sensorsBK44 Treatmentreplace all under P hoses, PCV, coolent hosesfuel filtertransmission service (change but not a flush)new belts
Do I need to do the upper link? What about Transmission mounts? Fuel pump? HO2 sensors? Is there anything else that's a must?
BTW, what's the best procedure for changing the H02 sensors, approaching underneath the hood or by reaching up from underneath the car?
As always, thanks for your help.
Stephen
I don't have a problem with the Q right now, (fortunately) but I was more concerned that there is something in the design of the exhaust valves which causes abnormal build up.
It looks like we will be keeping the car for another 3-5 years, so I plan on doing the following myself:
Plenum cleaningTB cleaningSpark Plugs (platium)knock sensorsBK44 Treatmentreplace all under P hoses, PCV, coolent hosesfuel filtertransmission service (change but not a flush)new belts
Do I need to do the upper link? What about Transmission mounts? Fuel pump? HO2 sensors? Is there anything else that's a must?
BTW, what's the best procedure for changing the H02 sensors, approaching underneath the hood or by reaching up from underneath the car?
As always, thanks for your help.
Stephen
-
greg_atlanta
- Posts: 1111
- Joined: Tue Jul 23, 2002 4:37 pm
- Car: 2008 G35 Journey Sedan, silver/black (no sunroof), 1992 Q45 (in a past life)
Q45tech wrote:As the average speed has gone up fewer accidents per car mile driven.......more focused.........but when they occur they are dozzies........SUV's are fun to watch as they flip in lane changes at these speeds..........we all cheer with glee as the cellphone flies out the window first in mid air!
:freak
ped So true!!!
:dogpile