'90 Grand AM with a few issues...

[Mr. Guy]

'afternoon, everyone. My poor girl has some issues. The car is mostly stock, LE loadout (wait, they don't load the LE with anything O.o) with the 2.5L Iron Duke (don't care what anyone says, I love the engine) and 3-speed auto transmission.

First off, the cooling problem. After I bought the car, the water pump started to go, and I replaced it. The car continued to run fine. At one point though, I got tired of the small leak just below the inlet hose for the radiator, so I decided what the hey, dump some stop leak into it. The radiator immediately clogged up, blocking most coolant flow through it once the car reached a certain temperature.
The funny part was, it circulated fine with the thermostat out and the car overcooling...but anyway, I replaced the radiator (it had gone for 240k miles, figured it'd done its job) and at the same time put in a new thermostat and coolant temperature sensor.
Now I have a problem---the temperature bobs up and down randomly. The normal highway temp. for this engine was just above the 1/4 mark, now it stays around that mark (it didn't at first, swinging from 1/8 to 1/2 or so randomly until I bought a new thermostat housing to replace the old cracked and leaking one), but it still goes up and down instead of holding steady.
My question is, could the stopleak have done something to the water pump to decrease its pumping ability? Its the only thing I haven't replaced since putting that crap in (won't ever do THAT again), the system seems to be clear of obstructions, so it shouldn't be doing this my gas mileage hasn't been the same since putting that stuff through, either...used to average 27-30mpg, now I'm lucky if I hit 25-27.

Next up, the strange little idle problem. The car idles roughly, has since I bought it. Along with idling roughly, the power levels go up and down---most noticeable inside the car, you can watch the dome light pulsate. I don't think it's causing any problems, since the car has done it since I bought her, and likely before that, but it's annoying. It doesn't only happen at idle, either; I can be going 60 down the highway, and the headlights will be randomly pulsing, dimmer and brighter.
There's nothing in the car that should be causing a power drain, everything is stock except my radio, and it's a little cheapy one that I got from Walmart. The battery has only ever died once, and that was from sitting for three days in the dead of winter. Autozone tested the alternator for me, and it checked out fine. Is this a common problem for this year and engine? Since I got the car I've replaced the spark plugs (at least three times), wires, o2 sensor, tested the EGR valve (fine), had the belts replaced, tightened the belts because the guy who replaced them forgot to, replaced the PCV valve, had the alternator checked in two different ways...etcetera.

One last thing for now. Recently, there was an emergency across the street from us, so my father started the car and, without letting it warm up or anything, went tearing full-throttle out of the driveway. When he got back, the car sounded like hell. The engine is noisy as it is, but now its putting out a sort of chittering/clattering somethingrather noise, seems to be coming from the passenger side of the engine. The car seems to run decently, a little hard to start every now and then, but I'm still worried about what kind of damage he might have done. I took off the rocker cover and tightened all of them down---for the most part they were all still tight---but that didn't help. Any ideas?


Every little bit of help would be greatly appreciated, despite its barebones design and loadout (not even Cruise Control or Hazard flashers ), I love the car, its fun to drive and used to get good gas mileage.

Assuming I could get it to run, anything I can do to squeeze more horsepower and fuel economy (preferably the latter) out of it? I've done some work on my T-Bird to make it more efficient, but I'm not sure where to start on a little transverse-mounted four-banger.

[grfnkl]

OK that was a bit long... but I will try to help you out a little.

For the coolant problems. The temp is generally around the 200-220 mark on these engines depends on how long the car sits running. The stop leak stuff, has caused problems for some people where it clogges up the coolant system and others like me are lucky enough not to have any problems as of yet. For instance on my 88 with the same engine, it actually has made my water pump quieter then it was since it's been going out for the past 10 years... .

The the rough idle, and pulsing lights. I would check the belts to make sure they are put in properly and are at the right tension. Anything more or less will cause problems with these engines. Another thought on this issue, is for you to check teh battery terminals make sure everything is tight and not corroded. Lastly I would check the battery. Your battery maybe going bad. Especially if you let the car sit 3 days in the dead of winter and it died... normally not a good sign. These engine do need a higher CCA to start them.

Lastly for your engine noise... It's hard to say if there was any "damage" done, but they are pretty strong engines. Everything seems to running fine other tehn the noise... An oil change may cure it. I know simple and random, but that has seemed to help mine with the chatter noise you speak of.

BTW. These are great pretty strong engines.... you do tend to go through a lot of spark plug ( do to valve cover leaks) and my 88 isn't even as fancy as an "LE" it's a BASE model!

[Mr. Guy]

Yea, hehe...sorry about the length.

200-220 is the city-driving mark for this engine, in my experience. But really, I haven't been able to compare that to anything, since there's nobody in the area with this year (everyone seems to like the nice, shiny, prone-to-strange-issues late models). 1/4 is highway, 1/2 (220) is city. *shrugs* It used to be so predictable, and almost is again, I think that stopleak is finally working its way out :P

Belts are tight, but they still flex a little bit, so I don't think they're overtight. The guy who put them on didn't bother tightening the bolts to hold them firm, so the belts were as loose as they could be for a while---the car ran the same, except for nearly redlining the temperature on a rainy day because of the belt slippage on the water pump.

Battery terminals are tight, alternator connections are tight, all connections in between seem to be good...but I'll check tonight to make sure. The battery itself has been fine ever since, not once have I gone out and she's failed to start.

My engine has always had the noise...it's just a lot louder lately. But eh, an oil change? It's about that time again anyway, so lets hope that helps it. Wouldn't mind getting this thing rebuilt, it really is a hell of an engine, and I can't really say anything bad about the car itself

Yea, the valve cover...the engine has a nice layer of oil all over it, never really paid attention to where to was coming from until I took that cover off. Then it was like "durr, should have replaced the gasket at some point"...but hey, the engine won't be rusting with that much oil on it.

Originally Posted by Wikipedia

The third generation Grand Am was offered in two trim levels, the LE, and SE. The SE wasn't available in 1985. In 1989, the LE became the base model.

So, you see...I feel your pain on the bright side, the less extras you have, the less that can go wrong~ at least we both have A/C!

Edit: Looking more, you have a better instrument cluster, nice rims (mine came with really crappy plastic hubs), a nicer stereo system...us '90 owners got screwed D:

[grfnkl]

Originally Posted by Mr. Guy

Yea, hehe...sorry about the length.

200-220 is the city-driving mark for this engine, in my experience. But really, I haven't been able to compare that to anything, since there's nobody in the area with this year (everyone seems to like the nice, shiny, prone-to-strange-issues late models). 1/4 is highway, 1/2 (220) is city. *shrugs* It used to be so predictable, and almost is again, I think that stopleak is finally working its way out :P

Belts are tight, but they still flex a little bit, so I don't think they're overtight. The guy who put them on didn't bother tightening the bolts to hold them firm, so the belts were as loose as they could be for a while---the car ran the same, except for nearly redlining the temperature on a rainy day because of the belt slippage on the water pump.

Battery terminals are tight, alternator connections are tight, all connections in between seem to be good...but I'll check tonight to make sure. The battery itself has been fine ever since, not once have I gone out and she's failed to start.

My engine has always had the noise...it's just a lot louder lately. But eh, an oil change? It's about that time again anyway, so lets hope that helps it. Wouldn't mind getting this thing rebuilt, it really is a hell of an engine, and I can't really say anything bad about the car itself

Yea, the valve cover...the engine has a nice layer of oil all over it, never really paid attention to where to was coming from until I took that cover off. Then it was like "durr, should have replaced the gasket at some point"...but hey, the engine won't be rusting with that much oil on it.
So, you see...I feel your pain on the bright side, the less extras you have, the less that can go wrong~ at least we both have A/C!

Edit: Looking more, you have a better instrument cluster, nice rims (mine came with really crappy plastic hubs), a nicer stereo system...us '90 owners got screwed D:

Well judging by the temp marks you seems to be running in the normal range. Expect the 220 in the city... for some reason these engine can get VERY tempermental. The highway it will tend to run cooler though. For the battery I only had the lights do that once and the battery ended up being bad... and it was brand new, so go figure on that one. The only other time I've seen lights flicker like that it ended up being an alternator, it would test good but there was a few bad diodes inside causing the flicker... Which could be the case. If you do a rebuild or a overhaul on teh engine it will last another billion mile... Mine only has 126K on it ( not running right now) If i put a battery in her she should start up like a champ and drive just like i parked her a year ago.

I'm pretty basic with the 88, I do have the a/c, power windows, a 1/3 decent radio, and I do have the rims on mine... the clear coat has gone bad making them a lovely yellow color, but i scraped that all off, and now they look more chrome. My gauge cluster is basic. My father had a base 87 g/a that had more options then mine... BUT it was also custom built from the factory for a family member of ours

[inafogg]

hello mr guy as far as engine noise it sounds like cam/crank gears when pontiac built the 2.5 these gears did not get enough lubercant.i work for gm dealer.there was a bullitin sent to dealers if a customer complained.sounds like a old sowing machine.the noise should'nt hurt engine but there is a fix. alot of work to do if this sounds like noise & would like to hear more post i'll answer good luck Mike

[Mr. Guy]

My first thought when I heard it was that the rocker arms had come loose, which is why I cracked open the valve cover. That's what it sounds like; loose, noisy rockers. They turned out to be plenty tight, and most interestingly, the engine didn't make the noise with the valve cover off...it was kinda fun running the engine that way, watching the valve train work and oil fling everywhere

But anyway, that's what it sounds like...noisy rockers. That annoying rattling sound they make. Still can't localize it, though.

On another, lighter note, I had to use a bit of power today to pass someone quickly to avoid getting smacked by another car...she seemed to have a fairly good amount of "oomph". I really haven't noticed any reduce in performance since it started rattling like this...though she does seem to be harder to restart once she's warm (I.E. after coming back out of the grocery store). When the car is cold, it takes two cranks to start; one to prime, one to fire up. When the engine is warm/hot, it can take three or, once, it took me four cranks to get it to fire up. On the other hand, sometimes it only takes one crank like it used to. Bloody confusing engine.

That's another thing I should mention---the noise goes away when the engine is above idle speed. Maybe there's just a bolt loose somewhere now, and the rough idling is shaking it...the engine runs smoothly above idle.

edit:

I do have the a/c, power windows, a 1/3 decent radio

You suck...all I have is manual crank windows. Starting to get jealous of people with older models...

[inafogg]

hi take a long screw driver or some thing simular put it on timing cover & listen i bet u will here it clearly there 99% its cam gears good luck Mike

[Mr. Guy]

I don't have an extra long screwdriver...or anything I could use in its place. But, had a bit of extra time, Googled it;

Originally Posted by http://www.rebuiltautoengines.com/pontiac-articles.html

TIMING GEAR NOISE
Timing Gear Noise Or Knock On
General Motors (Pontiac) 2.5L 1-4 Engines


The following information lists characteristics of timing gear
noise to assist diagnosis of problem cases involving the subject
engines.

Loose or improperly seated camshaft timing gears are usually
loudest when warm. They are sensitive to speed only, not load
sensitive. Cam gear noise will be noticed at a warm idle and
sounds much like a loose timing chain noise. It is recommended
to remove the drive belts and use a sounding device on the timing
pointer. This will provide a definite indication of timing gear
noise.

Timing gear noise is most noticeable at about 800 rpm. It can be
heard the loudest at the timing gear cover and at the oil pan
between #3 and #4 cylinders.

...yea. Didn't even think of it as a gear noise, but that fits. Any idea how much it's going to cost to get fixed?

Edit: what *is* the idle speed for these engines? I think mine idles lower than it probably should, but I'm still curious as to what the general RPM range is.

[inafogg]

hello its been awhile but parts $150.(guessing) we got about 6 hrs warranty time chilton time is about 1.3 times warranty time so 8 hrs depends on who is doing job local garage or dealer as far as labor rate goes. good luck

[Mr. Guy]

This? Clicky

Also, they have one with a "damper" for an extra $30. No idea what that is, though I'm assuming it's to reduce vibration in this rather shakey little engine. Worth dumping the extra funds in for it?

Last, but not least...any chance of me tackling this with basic tools to avoid the cost of labor?

[inafogg]

i'm not sure what the one with dampner is as far as doing your self you need atleast a floor jack(gotta remove engine/trans mounts)a puller these gears are pressed on & no matter who is doing you need to drill into oil galley plug to make sure gears get oiled but all in all it really is'nt to bad a job if your mech enclined if i can help feel free good luck mike

[xeroinfinity]

The gears on this 2.5 does not realy need a puller for the gears.
They'll probly fall off at this point in time. If so a scrwe driver should pop them off pretty easily as the top large gear is a fiber-ish plastic and it usualy broken in pieces.
Might pull your oil pan too and clean out the chuncks if it is broken into pieces.

If I was you Mr Guy, I would purchase a manual(if you dont already own one) this is a job but totally do-able. That damper is not needed realy.
If this were a DOHC engine then I would get the damper as they are noisey.

Good Luck and let use know if you need anything else.
And welcome to AF !

[Mr. Guy]

Hey guys, sorry for not replying in a while.

There's a gear drive conversion kit available for $135. How much longer would a solid gear-to-gear connection hold up than a timing chain? Is there any other benefits to converting to a gear drive, and all in all is it worth the cost?

Thanks a lot to you guys for your continued help on this...wouldn't know this stuff without you.

[xeroinfinity]

On a 90", its not worth it IMO .

You dont realy get any benifit out of the Gear drive since your motors not a "performance" engine.

Plus they are noisey.

[inafogg]

ok lets all get on the same page. your 90 g/a 2.5 engine should be a gear to gear set up.if there is a conversion kit to go to a chain set up it might help with the noiseyness.as far as it being better (timing chain)i dont think so. IMO