Hi Everyone,

I'm new to this forum and have looked around at previous posts and have found lots of possibilities to some of my issues. Forgive me if I've overlooked a same posting/answers.

My 2000 TL (171,000 miles) often has really rough hard starts and most of the time this hapens after we've been driving it for a while. Occasionally it will happen on a cold start, but most of the time it's with a hot start after driving a while.

When I start it and finally get it started, I'm almost afraid to keep it running as I often here a horrible clunking/knocking noise as if something is about to fall off. after several seconds with the engine reving and check engine light flashing, it finally drives normal, then engine light stops flashing and just stays on. I also have the shuddering always happening between 25-30 mph.

I took it to Advanced Auto and they scanned and gave me codes of P0174 and p0300-306. I know these codes are all misfirings, so would the shuddering be because of the misfiring as well?

My husband took it up to our mechanic tonight and told him about the p0300-306 codes (forgot to tell him about the p0174 code) and he said it sounds like the valves need to be adjusted. It does make a slight ticking sound almost like when an engine is low on oil sound.

Also, I just remembered our mechanic did tell us a couple of months ago that the engine mount is loose. I'm guessing this might be why it is shuddering but would it also cause the misfirings?

I also have to fes up and say I put mid grade gas in it just once, and it seems after that I've had this problem. I used to have a 98 TL that could run on low grade and I was being cheap one night when I filled this car up...yeah I know!! Deserved. I'm sure my cheap a$$ cost us $.

Do you think a valve adjustment will fix this and is this where I should start?

Thanks in advance!!

 

welcome to the forum we have your answers
the multi misfire codes usually mean ONE (maybe 2) ignition coil $50 has failed
Were the spark plugs recently changed then prob started?
coils are often damaged during plug change or they wear out on age.
Worn out spark plugs not good either, correct NGK 8$ each plugs in it. how many miles on them?

the shudder and a bad motor mount- likely front mount= as they all fail,
its a special oil filled and Vacuum boosted mount so its failure also causes a mystery engine miss, cost approx. 150$ for the part!

valve adjust never hurts every 100-150,000 miles but many ticks are heard in the engine by other parts
If you do this also clean the intake manifold egr systems, clogs and causes problems
Ck oil level to be sure~

one tank of mid grade didn't cause the problems- you're off the hook

 

Welcome K927!


1st thing is first. Unplug every coil one at a time if the engine doesn`t do anything when the coil is unplugged that would be the faulty coil. For 50 bucks a coil, it is not cheap so it` good to narrow it down to the faulty one.


But, also take off the top cover of the engine (10 bolts). If that is caked with carbon deposits it needs to be cleaned. If it is gunked you can be sure that the EGR valve, The IACV valve and the Throttle Body and Springs are also in need of cleaning and lube.


A bottle of TB cleaner and Brake cleaner will do the job and your time of course.

 

This sounds to me like the fuel boiling issue that some people here have experienced. Depending on when your local stations switch over to summer blended fuel, you may still be running winter blended fuel. We just switched over to summer gas 5 days ago in southern michigan, so depending on how much gas a station moves, I'm going to guess we're pretty much switched over by now. At a smaller, rural station, maybe not. People have tried different things, but try parking with you hood open to the safety catch, to release underhood heat. If it is the winter gas problem, it may go away by itself in a few weeks as you put in new fuel. My daughter had this problem, and complained to me, but I never took it seriously until it happened to me in the shop. It was knocking so bad, I thought the engine was going to come apart. Aside from that tight exhaust valves will cause mysterious cold engine misfires, and you're right at the mileage when it typically starts to happen. The valve adjustment will cure that most of the time.

 

Diagnose and fix the engine trouble codes first* misfires* and once u get that fixed focus on the next issues. aka mounts, egr cleaning, gas octane, transmission kiss of death etc. etc.

 

Thanks everyone, I appreciate it! I'll run all this past my mechanic.

 

as nick said- have your mechanic unplug the power lead to each coil one at a time with engine running
the rpm should drop slightly on a working coil
when there is no change = bad coil

the codes for misfire- the last number of each is a suspected cylinder, so he can try those first
rear cyl pass to driver 123
front cyl pass to driver 456

MUST reset ECU when you install or move a coil to another plug to test it
Open passenger door -see end of dash for fuse panel
remove CLOCK fuse for a minute and plug back in
that fully clears codes and resets the cars brain
drive and ck codes again
reset ECU again after new coil is installed

the spark plug on bad coil should be replaced, if its got more than 75-100kmiles on them do all the spark plugs. Wait till other items are resolved on running, then do valve adj with the intake manifold cleaning
Hopefully 1 coil solves it-- as it has for many of us on here
Note it uses NGK spark plugs $8 each

 

several of these jobs can be combined labor, you have to take off part a and b to get to c..so work on D is right there....

 

Welcome K927 !!!

~ Has this problem been ongoing or just start happening ? Any recent repairs or work underhood ?
~ When was the last tune-up of the motor ? May be time for Seafoam, new NGK plugs, air filter & PCV valve.
~ The misfire codes may possibly indicate a bad coil pack, fuel issue, vac leak, O2 sensor, etc. Reset "CEL".
~ Replace the motor mounts as they can cause tranny shifting problems. When was the AT fluid last changed ?

 

K9 add to list of questions
where you say engine starts and revs,,,is it going from 500 to 1200-1500 and back down like a see-saw?
that's likely clogged idle air control IACV, one of the parts to be cleaned within throttle body clean and intake manifold/egr port system cleaning,,plus valve adjust - all are located on the same job path

Sounds like your car went a long time without maintenance or tech is not familiar with the TL
Need the correct spark plugs for example. many are sold--- but only 2 work and are approved brands

 

Wow, the OP's post could be mine exactly, except my TL is a '99.

I'm going to change the plugs today, clean the EGR port and buy an ignition coil and see if I can figure out if one is bad.

I'm looking at iridium plugs, I've seen people recommend them, but at $10 a piece are they really worth it??? I've got 230K on the car and just need it to run for a couple more years if possible.

 

Which plugs should be used???

 

ps Its not unusual for any and all of these things to happen, that's why we know about each one. Front motor mounts go after 60kmiles ,,but may not be found for another 50kmiles! by then the side may have failed etc

the other things are natural occurring crud inside the engine, Its part of life
Most shops wont know of our specific egr system issues - not common to other cars

 

How can you tell if the front mount is bad?

 

NGK iridium or Platinum,,irids are stock in 99s
they are worth every penny
2 buck chuck plugs will not do

 

front mount will look collapsed, also look under car up at mount for small traces of oil. oil dust trail or small drips on garage floor
Many pics on here of before and after, ck diy list

apply vac gauge to mount and see if it holds suction but visual and oil are the fast clues..plus its a front mount soooooo its failed

 

Hey UNCatTech, .....at 230k and wanting a few more years, keep up with the basic PM stuff which is often neglected as the car ages. Check the "DIY" sticky for great info .

Things like the T-belt servicing, tranny fluid change, tune-ups and general cleaning of things like the EGR, IAC, TB intake, etc......tend to get put on the backburner.

But, by doing these things your TL will go the extra miles for ya. Fortunately ya have the more durable 4 speed tranny, but it still likes clean fluid to operate at it's best.

 

Uncat
making sure you know its not just the egr port,,the 99 has only one but its connected to a passage and the other end where egr valve sits- 2 holes under valve clog--get that passage all the way thru with a wire coat hanger and carb cleaner (no kidding)
lube egr valve stem with wd or similar- ck for free motion

 

Thanks this is good advice. I do try to keep up with all of that. I had the timing belt changed at 180K along with Trans fluid and tune up.

I replaced the plugs and cleaned the EGR port on Saturday. The port was completely blocked and the sleeve had slid down into the manifold. After this the car ran much better but it is still missing. I've ordered 3 ignition coils as I believe that to be the problem.

 

Thanks for the information.

Unfortunately I've had to do this particular activity several times so I'm up to speed on the whole EGR path. I did pull the EGR valve and clean from that direction also.

I am amazed that the engineers at Acura thought that small path would be enough. Most other cars that I have delt with have EGR paths that are half inch ID and larger.

 

I changed the plugs with NGK, cleaned the EGR port, and changed one ignition coil. The car is running great now.

By the way I found a pack of 6 ignition coils from ZZ Auto Parts for $100.

I took a chance and ordered them. Delivered in 2 days and the first one I changed did the trick. They are not identical to the OEM coils, but they were less than half the price. I'll let you guys know if they die in a few months. Here's to hoping that they last for years.

Plus now I have 5 spares also. If the Acura is like my Ford I'll be needing them shortly.

 

the 99 has 1 egr port, acuras fix under recall was to enlarge the hole to 8mm with a drill and insert a smooth barrel into the hole- the intent being less likely to clog in smooth bore
the next year it changed to 6 egr ports and we still get the problem
later years every 75kmiles this needs to be cleaned
a 99, I cant imagine how often you must need it!

 

for others: if you haven't removed the egr valve and cleaned the system all the way thru the length of manifold with a wire coat hanger (or correct egr path cleaning brush)
then its still messed up!

 

I would also in addition to cleaning the egr ports take a look at Throttle Body and Throttle Body springs. They might have carbon deposits that have accumulated over time. If so, clean the TB and lube the plate hinges and clean and lube the springs.

 

Mine was completely blocked this time and the sleeve they insert came out. It was obvious from the markings on the sleeve that it had slipped into the manifold, so I didn't put it back in. Cleaning that part is easy, so I will just start doing in on a time basis.

 

the entire length of passage that port leads to -thru the intake manifold to the egr valve- needs to be poked and rinsed clean