I replaced the water pump and timing chain tensioner over the weekend and I thought I’d share a couple of observations.

1. While space was indeed a bit tight, both jobs were pretty straightforward and doable without resorting to heroic measures like removing an engine mount or shifting the engine to get more space. I did remove the power steering reservoir to get at the timing chain tensioner cover plate, but that was pretty easy. It helps to have a variety of socket extensions and a ¼” drive ratchet because of the limited space.

2. This may sound like it contradicts 1. above, but once you have the water pump jacked out of the engine block, there is so little space between the engine and the car frame that the pump will slip out only by turning it to one particular orientation. There was literally only about a 1/16” clearance between the pump and engine/frame.

3. Even though I drained the radiator and removed the thermostat housing in an effort to drain all the coolant from the cylinder heads, there was still about ½ pint of coolant left up in the head that drained into the engine when I removed the water pump. How do I know? Because I had removed the oil pan (more on this later) and the coolant ended up on my garage floor after draining through the engine. So if you replace your pump, be sure and change your oil afterwards because you are going to get coolant in your oil. It’s best to drop the oil pan because the oil drain plug does not entirely empty the contents of the sump. There is a cylinder head drain plug behind the headers, but I could not get it loose using the hand tools that would fit behind the header, and my air tools couldn’t get to it.

4. Removing the water pump requires using two M8 bolts as jacking bolts. Be sure to get these before you start your job.

5. I spent $80 on a new water pump only to find out that I probably needed to replace only a couple of dollars worth of leaking o-rings that had hardened and taken a set. The pump itself and pump bearings did not appear worn in any way. Oh well, might as well go ahead and replace it while I had the SC bracket off.

6. The timing chain tensioner was not difficult to do except I didn’t try hard enough to retract the spring and plunger and lock them in place with a push pin before unbolting the tensioner from the engine, so I gave up on that and just tried to be very careful when removing the tensioner. Well, you guessed it, the plunger and spring popped out and fell behind the timing cover. D’oh!! No problemo, I thought, I’ll just fish around with my magnetic pickup tool. I got the spring right away, but I spent about two hours (interspersed with changing the water pump) trying to find the plunger. That is why I dropped the oil pan. I thought maybe it might have fallen all the way down to the bottom, but no such luck. After consulting the Haynes manual and the FSM, I convinced myself that it had fallen into a place where it would do no harm. Still, the pucker factor was going to be pretty high when starting the engine, so I decided to fish around one last time and voila!, it finally took the bait and out it came.

7. In retrospect, going through the difficulty of retrieving the plunger and resorting to dropping the lower oil pan was a bit of serendipity, since I would not have known about the coolant draining into the oil sump otherwise.

 

How did you take out the timing chaing cover plate? You had to remove the side engine mount right?

 

No, the only thing I did to improve access to it was to take off the power steering reservoir and move the large power steering hose over towards the firewall and away from the work area.

 

Thanks for the write-up. I envision myself doing this sometime in the future. Did you find the Haynes manual sufficient for this project? I'm still searching for a FSM.

 

In most cases the Haynes manual directions are just as good as the FSM, and the Haynes has good photographs to go along with the written instructions. The FSM has drawn illustrations, and sometimes it's hard to tell what's what. On the other hand, the FSM covers a lot that Haynes doesn't (transmission rebuild, for instance).

 

How's the new pully?

 

It looks very pretty sitting on the blower shaft, back in my workshop, thankyou. ASP did an excellent job. I haven't put the blower back on yet cuz I got a charge air pipe mod going on. Details later.

The old pulley was easy to get off without damaging it with the help of a propane torch and gear puller. I heated the new pulley by resting it on a 100 W light bulb until it was good and warm (hot, actually) and it slipped right on. Then I had to pull it off and reinstall it because I put it on backwards. At least I discovered my mistake right away and not after I mounted the SC bracket onto the engine.

 

What made you decide to do this? Car overheating? I might have to do this soon.

 

I was getting a little bit of coolant leakage past the water pump o-rings. If you do it, get some extra o-rings along with the water pump (the water pump comes with new o-rings, btw). Chances are it's just the o-rings that need to be replaced and you can return the water pump for a refund. I decided to go ahead and replace the pump even though it looked fine because changing a pump is a lengthy job for me since I have to remove the supercharger setup in order to get at the pump.

 

That magent tool came in handy just like it did for me as discussed in your post before the install. Were you in shock when the plunger fell into the timing chain case. When it happen to me I just stood there for 10 mins in shock. Bought the magent tool after that. Best $5.00 I ever spent. Got both the plunger and spring on the first try.

How could you even see the tensioner. Did you use a mirror?

Even though you had to remove the oil pan you saved a hell of alot of time and money. Good job

 

Actually, it was your post in the other thread that got me a little cocky and careless about it in the first place! I figured I wouldn't have any problem at all getting the spring and plunger out, based on your experience. After the first five or ten minutes of fishing around, though, I started to break out into a cold sweat and panic set in. That's when I dropped the oil pan. After taking a look in the Haynes manual and FSM, I pretty much comforted myself that there was no where it could have gone that would damage the engine. I was still very happy and relieved to get it out, though!

I was able to see the tensioner pretty easy, at least enough of it to get the job done. What was difficult was getting the plunger retracted with one hand and pushing in a pin to lock it in place. There's not enough room for both hands down there at the same time, so I gave up on that and tried to remove it with the plunger and spring unrestrained. Bad idea.

 

How many miles are on your car?, just curious.

 

I don't know what this looks like... so I am just asking cause I am sitting here trying to figure this out.

On all the water pumps I have done (mostly Yotas) I can't think of any reason why I would get coolant in the oil...

...how is that happening here? Is the TC Cover covering the water pump?

 

philly96maxima: 136k. Still going strong.

Entropy: The water pump on a Maxima is internal, behind the timing chain cover. The pump is driven by the timing chain, and is fed engine oil which drains back into the oil sump. It is cylindrically shaped and has two o-rings at its middle. On the other side of the o-rings is the impeller for circulating the coolant from the cylinder heads and out through the thermostat housing to the radiator. When I pulled the pump out of the block, the remaining coolant in the front cylinder head was released and drained down into the engine via the engine oil drain passage.

 

Alright, that makes sense...

Although I can see the advantage in longevity that an oiled water pump would have... how much risk is there that a failure could leak water into the oil and cause greater damage than necessary from a small leak?

Obviously there isn't that much - I have 150K on my car with 0 probs... but I am curious if this is a possibility.

 

Stephen MAx did not remove the whole timing chain cover, only the tensionner coverplate on the firewall side, about 4 inches x 4 inches. (Correct me if im wrong) There is also a water pump cover plate on the front side, (about the same size) which he removed. I assume both plates can be removed without removing the engine mount. Removing the wheel well inner fender also helps clear the way. It is only attached by 4 screws: easily removed.

Stephen: congratulations for your work and thanks for sharing it. Your story will inspire me if I need to do same.

 

How do you know when you have to change the timing belt tensioner? Honestly, I dont trust myself enough to do it - I'll probably have to go to a mechanic to get it done.

 

i think u could have solved the coolant leak into the motor oil problem.. by looking for the water pump drain plug... (its located rite on the bottom left of the water pump) that would have drained the coolant anywhere near the water pump... so u wouldnt experience any coolant leaking into the oil pan.

 

You get a rattly valve train noise at startup in the morning. Eventually oil pressure pumps the tensioner up and the noise goes away after a few seconds.

 

I am unaware of a coolant drain there. I know of a drain plug on the side of the engine behind the headers. I tried to remove that plug but it was too tight to loosen with hand tools and inaccessible with air tools.

 

There is a weep hole so that if coolant leaks past the first o-ring it drains out without getting into the engine. The weep hole leads to an opening at the junction of the upper oil pan and the engine block, and leaks down between the AC compressor and the engine. It really scared at first, I thought maybe I had a cracked head or block, but the Haynes manual set me straight. That is what led me to change the water pump. In retrospect, I don't think the pump needed replacing, just the o-ring.

 

Yeah, I don't think there's a drain plug there. If there was, it would just drain into the timing case, which wouldn't solve the problem at all.

 

What do you mean by rattly valve train noise at startup? I get two noises when I start up, like a crunching noise and the second one kind of sounds like sqeeking belts. Could one of those be a rattly valve train noise?

 

Crunching noise? I don't think I've ever had that. Typical noises for a 4th gen Maxima are:

a raspy, mechanical squeal, which is the starter gears needing to be regreased (see motorvate.ca). This occurs only while the starter is being engaged.

a squeak or squeal, which is a loose belt. The squeal may go away after the car is started, but then comes back when you turn on the AC.

a rattle that occurs right after you start the car and then goes away after a second or two. That is valvetrain noise due to a worn timing chain tensioner.

I've never heard of a crunching noise coming from the engine. Does it happen only when the starter is engaged, or after the engine is started? How long does it last?

 

It only happens when it is kind of cold outside and my car has been sitting all night. It is pretty loud like metal crunching on metal. It only happens only right when I turn the key and then goes away like quarter of a second after the car has started , I am guessing it is my starter. Also on the belts? do they need to be replaced or how can I get them tighter? Also I noticed that the squeel after it rains, is it because of mositure, because it is pretty humid here in Houston.

 

The squeal is definitely a loose alternator/compressor belt. The other noise is most likely your starter. You might try regreasing the gears in the starter as outlined in motorvate.ca

 

Excellent information. I'm contemplating the same thing for my 97 SE (106k, engine has been sounding slightly more squeaky over the last 5k).

Do you have ABS on your car? I found it to be a major complication when changing fuel filters, and I don't remember if there is any ABS piping on this side of the engine.

Also, to diagnose the source of my noise (it's not the belts nor the starter), I'll try removing both the water pump and tensioner covers and seeing if that helps me pinpoint it. Would you recommend just replacing both?

Dave

 

No, I don't have ABS, but I think all the ABS stuff is on the driver side of the engine bay.

I don't quite understand what you are thinking of replacing. The tensioner and water pump or the covers? Sorry if this is a stupid question.

 

Make sure you don't stick anything in there...that would be a great way to lose a finger, or to bind up the timing chain and blow the engine.

 

Thinking of replacing the water pump and tensioner. Only symptom is extra engine noise near timing chain, oil is clean. I figure removing the covers will help me pinpoint the source of the noise. Then I may remove the accessory belt or loosen them a touch to see if its the pulleys. Reading more though, instead I may just replace part-by-part starting with the pulleys, and then doing the tensioner, and last the water pump. Theory being that I replace the least expensive and most likely to fail first.

Dave

 

Good plan. I think I could have saved $80 by just replacing the o-rings around the water pump. The pump itself had no play in the impeller bearings and seemed like new. I don't think they really wear much in the first 100-150k miles unless you've had oil distribution problems or seriously over-heated the engine.