Change timing belt & water pump, now engine "kicks

[alcyon]

My timing belt was changed in December 2008, even though i have not hit the 100,000 km mark on this belt, i decided to swap it out because its almost 8 years old . So today i sent the car to a mechanic to change the belt, and he recommended changing the water pump too. So when i took the car in the evening, i kind of noticed it is hesitating on acceleration , and even while cruising. start up and idle is completely normal, but accelerating in any gear, and cruising steadily it kind of kicks back very subtly, i don't hear any misfiring but i feel it. Could the pulley be off a tooth? I was pretty [censored] to say the least. The mechanic promised to look at it tomorrow and pinpoint the source of the problem. Engine is a carb Mitsubishi 4G13 12V that was running great before the timing belt change. Any other things that could be the cause ?

 

[krismoriah72]

Symptoms of timing belts. One Tooth: It will idle like normal and the exhaust will sound fine but cruise and WOT the car will feel like you've got no power and in most cases will hesitate and misfire. Two Teeth: It will sound like somethings "knocking" which is likely the pistons kissing the valves. The car will start and idle but if it sounds like somethings knocking just because it starts DON'T DRIVE IT! Three Teeth: Your bending valves, the car more than likely won't start, & you'll have ZERO compression.

 

[Astro14]

Yep...off by a tooth...

 

[SwampSurvivor]

Hopefully the mechanic will fix it up for free

 

[alcyon]

Yes he will, mechanics here are usually good in that department.They do want to keep their customers after all. I just hope its just a simple problem of being a tooth off, and nothing else, i want my old car back. Thanks Krismoriah72 for the lowdown.

 

[HerrStig]

Is that an interference engine?

 

[440Magnum]

Could be off by a tooth. If the cam is a tooth advanced, you'll probably feel a little better performance right off idle, but it will lose power at high RPM. If the cam is a tooth retarded, it'll be the opposite- feels like a slug at low speed but wakes up and pulls harder at high RPM.

 

[demarpaint]

Hopefully he fixes it and no damage was done.

 

[CT8]

Belt installed wrong? If so rookie move.

 

[Trav]

TB is off a tooth, one tooth isn't going to cause any valve/piston contact issues, easy fix.

 

[Vikas]

How difficult or easy is this type of mistake? Shouldn't mechanic check this twice before buttoning up? Shouldn't he notice it on the test drive? A professional mechanic should never ever screw up a job like this.

 

[alcyon]

He rechecked the timing and insists its correctly aligned. So he doesnt know what is the problem. I had thricespark plug cables problem in the last 15 years so perhaps its the cables after all. Will go to another mechanic to check this possibility.

 

[supton]

It's a 1991, right? Could be timed perfectly, but something else broke. Likely something touched by the job, but occasionally something completely unrelated just gives up the ghost.

 

[alcyon]

Getting sick of these mechanics who seem to know nothing. I decided to check my valve lash and did find them rather loose. I have tightened up the clearances to spec. Also i have cleaned up the distributor and replacing the spark cables. Will report back on the results.

 

[alcyon]

Well after everything is done i started up the car and the idle speed was above 1000rpm but within 1 minute oil and the coolant temp went up quickly and the oil pressure started to drop and idling became weaker. I stopped the engine and called my brother who is good at these things and he said the valve clearance is probably too tight. I quickly opened up the valve cover again.sure enough it was hot. I tried sliding in the appropriate feeler gage and sure enough it couldnt go through. I re set all clearance since the engine was hot and when i got to the last inlet valve, the very last inlet valve screw sheared at the screw head. Being a sunday night, i cant buy the parts so the car will be sitting for a day. Will buy a new screw tomorrow and set it to the next inlet valve with cold clearance. Will report back if the engine idles smoothly and if get back my low end power.

 

[pottymouth]

Sounds like your mechanic might know more than you think.

 

[Vikas]

Here yet another example of valve clearance adjustment making things worse than before.

 

[Trav]

Originally Posted By: alcyon

Engine is a carb Mitsubishi 4G13 12V that was running great before the timing belt change. Any other things that could be the cause ?

You made a mistake messing with the valves. It was running great as you say before the belt change so nothing happened to the valve adjustment between that time and the belt change. It was the either the belt off a tooth or something got disturbed during the job. Now you throw a botched valve adjustment into the mix is just making a bad thing worse. IMO the best thing you can do is to replace the screw, get them adjusted on the loose side then pay the mechanic to set them properly then go over the job to find the problem. Whatever you do don't mess with the distributor, timing or carb. That would really turn a three ring circus into a full blown fiasco.

 

[Vikas]

The person who thinks he can adjust the valves should certainly be in a position to determine if the timing belt was installed correctly or not. He does not need to take the word of his mechanic on it.

 

[Trav]

I cant speak to that, some aluminum head valves are hard to get adjusted right. If they are a real PITA I use a dial indicator on them, its much more accurate than trying to get aa good swipe on a feeler gauge at a weird angle. My only point was don't do anything that may create more possible problems until you get the original problem squared away.