I have a 1994 Acura Integra LS automatic with 165k miles. I had a valve adjustment done on the car. Immediately after the work was done and since that time the car has had poor gas mileage, a very rough idle, and loss of power. I had abolutely none of those problems before the adjustment. Before I take it back into the shop I would like to know if a bad valve adjustment could be the source of these problems and how it should be remedied. Also, are there any long-term risks associated with a bad valve adjustment?
Normally a valve adjustment itself doesn't bring about those problems - it sounds like the timing belt has slipped. First and most critical question - is this the original timing belt? If the answer is "yes" you are driving on borrowed time.
If the belt was changed a few years ago when it was due, the danger of a flubbed valve adjustment is that the valves may have been set too "tight." That often leads to burned valves. "Loose" valves make a lot of clatter but are not a risk of damage.
If the timing belt jumped because the engine was turned backward (clockwise) during the valve adjustment the shop owes it to you to make it right, even if (*especially* if) valve damage has resulted. If the belt is overdue for replacement - that is, if it is the original - you may have some bargaining to do. They can't be wholly responsible for failure of a 12 year old belt.
It was a local Honda dealership. So, if I suggest to them that they "jumped my timing belt a tooth or two" they'll know what I'm talking about? If I did burn a valve because of their bad adjustment wouldn't it be their responsibility?
That's good. The thing to do is take it back and let them know it is running much worse and you are confident they will make it all better. I'm sure they will live up to your hopes!
concur with mike & curly - belt skipped while it was being turned the wrong way. have them re-time the cam belt and adjust the belt tensioner correctly, then you should be set. clearly it wasn't done properly when the belt was last changed - another symptom of incompetency that would make me very wary.
which brings me to the next point: for the future, i'd consider finding another shop. you got the junior junior wrench's assistant here, twice in a row. personally, i'd rather have this critical and potentially /very/ expensive stuff done by someone with both experience and a reputation to worry about. independents can be great in routine stuff like this because they've done their time at the dealership, know their trade, and are in business to stay in business, not depend on a captive audience like the dealer.
I also suspect your timing belt is very loose and now might be a good lime to replace it and the tensioner. My tensioner was bone dry in my 95 Civic VTEC with 190,000 miles. The timing belt was orginally done by the dealer at 110,000 and had over 1.5 inches of deflection at 190,000 vs. a little over .25 inches after the second belt change. And most of us would agree that these belts don't stretch! Good luck.
Update: I brought the car in and pointed out the issues you guys brought up. It did turn out to be that the timing belt had, in fact, jumped one tooth. However, they insisted that it was purely a coincidence and the valve adjustment had nothing to do with it. I asked why would it jump immediately the day after the valve service. He replied although there is only 65k on the timing belt, that because it has been over 6 years since it was replaced that the timing belt probably is due and a little worn and that could've cause it to jump. I told him I didn't agree with that scenario, but he wouldn't concede.
Seeing that was going nowhere, I then asked assuming that is was a coincedence why didn't they notice that before the last two times I was in with this problem? He replied that they did check the timing and it was just a little off -- but still within the normal range. I then asked to talk to the service manager who just happened to be out of the office.
When I talk to the service manager what "proof" can I show him that the valve adjustment could have caused the timing belt to jump a tooth? I'm not a mechanic by any means, so I just can't say "because I saw it in an online newsgroup." Is there something official from Honda or Acura that I can find online?
Anyway, the car runs great now. No more rough idle at all. I haven't gone through a tank of gas yet, but I'm pretty positive that will be better, too.
Not sure how adjusting the valves would cause the belt to slip. Possibly, if the belt were loose and the engine was rotated backwards aggressively, then maybe. If the valve timing is now advanced (i.e. valves opening too soon), that could indicate that the slippage occurred in that manner.
If they are complete idiots, anything is possible.
it's not the actual valve settings that cause the belt to jump, it's the fact that if the belt is already loose, when the technician
*incorrectly* turns the crank the wrong way, a loose belt will jump. and here's the clincher, not only is a loose belt easily apparent when you get the cover off, you can /see/ it jump as the crank rotates!!!
bottom line:
if the belt was loose, it wasn't done right in the first place - belts don't stretch.
the tech turned the crank the wrong way, hence the jump.
checking for loose belt is part of the job when doing the valve lash!!! if that wasn't done, and they sent it out the door with a belt that was not only loose but jumped, it's /definitely/ their problem. just like it's their problem if they work on the wheels, don't tighten the bolts on replacement, and one falls off on the freeway home.
the belt tensioning procedure is all in the honda service manual, including instructions to only turn the crank in one direction. i'd call honda usa's customer service line and talk it through with them. this vehicle wasn't serviced right, and you shouldn't have to pay for the remedy to their error.
Well, there you go. I assume you saw it jump on the cam sprocket.
And I am pretty sure that if the belt slipped while the engine was turning forward, the valves would always be retarded. If the valves are advanced, it could only happen when the engine was turning backwards and it indicates that the mechanic made a mistake when adjusting the valves. I'm guessing that he isn't very familiar with Hondas.
Right. Fortunately it was in front of my face as I was moving the crankshaft and I was watching it to align the timing marks. The belt lifted up almost immediately as the cam gear began to move. IIRC I had planned to turn the crank quite a distance, so I didn't stop in time to prevent the belt from jumping the whole tooth.
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