L27 Regal losing coolant, light knocking noise

[xtremerevolution]

So I just rolled onto the 183,000 mile mark, and I've got some issues that are currently preventing me from driving this car. This kinda sucks considering I'm saving quite a bit on gas each week driving this instead of the Bonneville, and I've just done a bit of suspension maintenance as well to get rid of nearly all suspension noises.

 

First off, I'm losing coolant, and I don't just mean a little. In the past 3 days I've replaced a whole gallon of coolant. The oil seems perfectly fine (which I just changed a few days ago), so I'm not sure if it would be suffering the same LIM failure that the 3.1's have. Its a possibility, and I have LIM gaskets on hand if I need to do that job.

 

However, I do see some wet spots around the engine, particularly on the driver's side a few inches below the base of the intake manifold plenum (or whatever that plastic thing is called). Its enough to lead me to believe that its where my leaks are coming from. While the car is on, I really can't tell where its leaking and there are no leak stains on the ground where I park, or at least none that I've noticed. I just replaced the radiator cap thinking that was leaking, and that certainly isn't the problem. A few threads ago I replaced the pot metal fitting that connects the water pump's hose to the engine block. That hose was also replaced at the same time. The radiator itself doesn't seem to be leaking anything, though I'll have to double check that to be 100% sure. I figure if I'm losing half a gallon during an 80 mile commute, I'd notice where the leak is coming from. There's also absolutely no smoke coming from the exhaust, and engine temps aren't anything unusual.

 

As a bit of background information, I had just changed my oil recently after 6,600 miles. I've been using fully synthetic this whole time. During this last oil session, the engine seemed to idle a bit rough and I could feel the vibrations in the steering wheel. Those vibrations are no longer there now that I've changed the oil. Another thing to note is that for the past 2,000 miles, I've had about 1/4 a small container of seafoam in the crank case. Probably not the best of ideas, but given 4.5 quarts of oil was in there, I'm doubting that would have harmed much. During that whole 6,600 miles, I only lost half a quart of oil.

 

Lastly, I've got some knocking in the engine. I don't know where its coming from or whether its inside the engine or on the outside, but its audible if you stick your head in the engine bay, and sounds exactly like the knocking you'd hear if someone lightly knocked on your front door. The noise is constant and follows the rhythm of the engine's exhaust noise.

 

Right now I feel like tearing this whole engine apart to figure out what the hell is going on, because I need it fixed and working once it starts snowing, and I'd rather not wait till it gets cold to fix it. Its perfect weather for working on a car right now as Chicago's heat is just passing away (I hope).

 

Any ideas? If I tear it apart I'll also replace the throttle body gasket (which I also have one of on hand).

 

Keep one thing in mind though. I have absolutely no idea how long these problems have been going on. My guess is anywhere from 200 to 2000 miles.

[spiderw31]

I'd expect that if you were loosing that much coolant into the combustion chambers, you'd be seeing crazy plumes of smoke out the exhaust. However, I'm pretty sure that if you were losing it outside the engine, there would be no way on earth you'd miss it. As a result, if you are absolutely positive the coolant is NOT in the oil, I'd have to say you're losing it into one or more cylinders... I don't think there is any other place for it to go

 

I'm guessing a gasket let go in a big way (possibly a head gasket), and coolant is entering a cylinder.

[xtremerevolution]

I'd expect that if you were loosing that much coolant into the combustion chambers, you'd be seeing crazy plumes of smoke out the exhaust. However, I'm pretty sure that if you were losing it outside the engine, there would be no way on earth you'd miss it. As a result, if you are absolutely positive the coolant is NOT in the oil, I'd have to say you're losing it into one or more cylinders... I don't think there is any other place for it to go

 

I'm guessing a gasket let go in a big way (possibly a head gasket), and coolant is entering a cylinder.

 

That's what I was worried about, but the engine is running perfectly smooth.

I checked the coolant again today after a 35 mile commute and it was at the perfect level. My guess is that when the radiator cap failed, it lost enough coolant to where every time it needed to suck it back in, it would suck in what was left in the reservoir to replenish what was lost in the system. Apparently it did that twice for a whole gallon of coolant, and now it seems to have leveled off. I'll have to check again when I drive it home tonight and see if the level has changed.

[spiderw31]

That is possible, but that would have to be an enormous air pocket in the cooling system for that to happen

 

I would be a bit concerned about the knock you are hearing too... I'd pay real close attention to it and try to see where it is coming from.

 

Hopefully it is all a minor issue though.

[xtremerevolution]

That is possible, but that would have to be an enormous air pocket in the cooling system for that to happen

 

I would be a bit concerned about the knock you are hearing too... I'd pay real close attention to it and try to see where it is coming from.

 

Hopefully it is all a minor issue though.

 

Yeah hopefully. I think I'm going to get some engine restorant and put that in here. 2 oil changes ago I used it and it quieted the engine down very well, and I noticed a big difference in the low end power it had. I also checked again today and couldn't hear the knock anymore. Even when I did hear it, it was barely audible. I wouldn't know where to start as to where it might be coming from though.

[spiderw31]

It is quite possible that the knock is just 183,000 miles of wear becoming audible, so it may not be a big deal. I would get a stethoscope though, and see if the source could be located. Just for peace of mind, I like to know where any noise in my engine is coming from.

[xtremerevolution]

It is quite possible that the knock is just 183,000 miles of wear becoming audible, so it may not be a big deal. I would get a stethoscope though, and see if the source could be located. Just for peace of mind, I like to know where any noise in my engine is coming from.

 

lol, I do too, but the engine runs perfectly strong and even the knocking noise is only audible if your head is sitting 1 foot from the intake plenum.

 

And these 183,000 miles have been some pretty serious wear. I've been driving the hell out of this motor for the past 117,000 miles. I definitely don't baby this car.

 

Anyways, its my lunch break now so I'm going to grab some fast food and check the coolant again.

[xtremerevolution]

Well I drove out to lunch and checked the coolant 3 times (before I left, when I got there, and when I came back), and everything was the same as the way it was last night.

 

Perhaps it really was just the radiator cap...

 

I also put in some engine restorant, which made a pretty big difference last time in making my engine smoother and quieter. Definitely works well.

[spiderw31]

Good deal... its always nice to find that what appeared to be a major issue was really no problem at all

 

And yeah, if you can barely hear the knock from about a foot from the plenum, it probably isn't a big deal (unless it is louder from underneath the car).

[xtremerevolution]

Good deal... its always nice to find that what appeared to be a major issue was really no problem at all

 

And yeah, if you can barely hear the knock from about a foot from the plenum, it probably isn't a big deal (unless it is louder from underneath the car).

 

Turns out it wasn't the issue I thought it was. Today when I came back after going to lunch with my girlfriend in the Bonneville, I saw a nice puddle of coolant under the regal.

After spending 15 minutes under it trying to figure out where the leak was coming from, I finally found it coming from the water pump. So I ended up taking off the water pump and finding a completely destroyed gasket. Yep... New gasket going in tomorrow.

[Captain Ficho]

Good deal... its always nice to find that what appeared to be a major issue was really no problem at all

 

And yeah, if you can barely hear the knock from about a foot from the plenum, it probably isn't a big deal (unless it is louder from underneath the car).

 

Turns out it wasn't the issue I thought it was. Today when I came back after going to lunch with my girlfriend in the Bonneville, I saw a nice puddle of coolant under the regal.

After spending 15 minutes under it trying to figure out where the leak was coming from, I finally found it coming from the water pump. So I ended up taking off the water pump and finding a completely destroyed gasket. Yep... New gasket going in tomorrow.

 

Beauty, that's what I like to hear. That was like when I thought my Cutlass' oil pump o-ring was gone, but it just turned out to my oil pressure sender had broken and was spitting oil, all in all a quick cheap fix.

[xtremerevolution]

Good deal... its always nice to find that what appeared to be a major issue was really no problem at all

 

And yeah, if you can barely hear the knock from about a foot from the plenum, it probably isn't a big deal (unless it is louder from underneath the car).

 

Turns out it wasn't the issue I thought it was. Today when I came back after going to lunch with my girlfriend in the Bonneville, I saw a nice puddle of coolant under the regal.

After spending 15 minutes under it trying to figure out where the leak was coming from, I finally found it coming from the water pump. So I ended up taking off the water pump and finding a completely destroyed gasket. Yep... New gasket going in tomorrow.

 

Beauty, that's what I like to hear. That was like when I thought my Cutlass' oil pump o-ring was gone, but it just turned out to my oil pressure sender had broken and was spitting oil, all in all a quick cheap fix.

 

lol. I wish it was quick. I had to let the system bleed (because I was dumb enough not to bleed it ahead of time) in a bucket under the water pump, then had to take off the pulley bolts, the belt, the water pump bolts, and here's the great part. I used gasket remover to get the old cardboard-feeling gaskets off, which was a total PITA. The best part is, if you get any of that shit on your skin, it starts to burn. Seriously, that shit will F*** you up.

 

So after getting the gasket off the engine and off the water pump, I put in a nice new felpro gasket, tightened the bolts according to torque specifications in my haynes manual (which was VERY handy to have), put they pulley back on, belt back on, and then spent the next 10 minutes re-filling the cooling system. All in all that took a pretty long time as well.

 

But I was glad the whole thing only cost me $5 (one gasket and 2 gallons of premixed coolant).