Q45 Oil Pan R&R advice

[Q451990]

I've been wondering about this. After a typical chain-guide replacement, why does anyone bother cleaning up the oil pan of plastic parts?

Something must be wrong with my assumptions below:a) Big pieces (once they've already fallen) sit on the pan bottom harmlessly?b) Smaller chunks get sucked into the pickup but stopped by the screen?c) Teeny tiny bits might get past the screen (but a few bypasses thru the engine should soon trap them in the oil filter)

Is it that the smaller chunks clogging the intake screen impede oil flow?

You're forgetting the velocity involved with the moving oil... the large pieces are churned around, breaking them up into smaller pieces causing the clogged pick-up. Also remember that the oil level is very near the top of the pan on a normal basis, so it's possible that a chunk that's churned to the top could get thrown back into the oil pump chain.

I vote for going ahead and removing the front cover while you're in there. The biggest thing you'll need to buy tool wise is a chain wrench.

Heath

[tangalora]

... a chunk that's churned to the top could get thrown back into the oil pump chain ...

I've since spent hours researching this on NICO and, after having seen the cracked lower timing cover (of unknown origin) and other horror stories, consider me duly forwarned.

The specific suggestions were that a large chunk can wedge between the chain and sprocket, possibly breaking the chain or cause the chain to slip a tooth (one crank tooth or two cam teeth bringing the engine near the danger zone of embedding a valve in a piston head).

The smallest chunks (which slip past the mesh screen) can, according to other NICO posts, score the oil pump vanes. However, in stark contrast, with all the chain guide failures reported, nobody yet seems to have reported any major problems with oil pump failures (yet the oil pump is a standard replacement in chain-guide jobs). The good news is the oil pum replacement is cheap enough, even if it's not strictly necessary.

The real culprit if the oil pan isn't cleaned out might be lowered oil pressure due to that oil sump being almost completely blocked off. I'm kinda' sorry I didn't do a before-and-after check to see the difference in oil pressure after cleaning the sump screen of debris.

In my case, the oil pickup sump opening "smile" was clogged completely.Who knows what that did to oil pressure; or to oil volume.The only way I could see the mesh screen was to flick a few particles away.There were virtually no small (light) pieces left in the oil pan (almost all were sucked into the sump).

My two large ribbed (tension side?) chain-guide chunks were, strangely, deep in the lower level of the oil pan.I had to fish my hands all around under the baffle to find them at all.I would think this "fishing" expedition would be difficult to impossible to perform from above the small opening left by removing the lower timing chain cover. Even with the suggested vaccum-suction tools.

I've written a one-page summary of all I can from the dozens of NICO threads on the chain-guide repair.I'll try to post that complete summary separately for review (after I add the the requisite FSM section information).

[tangalora]

For the next person doing an oil pan R&R, you may wish to note a thread I just found while researching how to replace Q45 chain guides:http://www.nicoclub.com/zerothread?id=48852 (www.nicoclub.com/zerothread?id=48852)

In that thread, John Nordling appears to have removed his Q45 oil pan WITHOUT removing the front engine gusset (he would almost certainly have mentioned that if he had).

Note that his method (see below) is very different than ours; but also note our oil pan was dented and probably pushed over closer to the gusset than is stock. We'll certainly find out if that is the case when we put the new oil pan on whether that 18th hole would have been covered by the gusset had the oil pan not been damaged and dented by the curb.

As for the oil pan, that job calls for patience and perseverance. I followed the shop manual, but it is verrrry light on details! So, I just used common sense. First, I fabricated a left side engine slinger and supported the engine with an engine hoist. This was easy because so much is off of the engine. Then I supported the transmission with an ATV jack, which is a very cost effective transmission jack with about twice the lifting capacity. Cost me $59 plus tax. Finally, I removed the transmission mount and the exhaust system mounts attached in the same area.

About this time I decided I needed to have more room to crawl around under the car, so I put the front of the frame on a pyramid of three railroad ties on each side, using one railroad tie under each of the rear wheels. These things really work well and give you that margin of safety when you're crawling around underneath. (Actually, I use treated highway guard rail posts cut in half.)

Now, I crawled underneath, pulled the sway bar, the steering rack, the tension rods, removed the lower suspension arm from the cross member, tied up wires and hoses, pulled the motor mounts and finally the crossmember. After that, dropping the pan was just a matter of pulling the bolts and a light tap from a rubber mallet.

Probably more than you wanted to know, but I just don't think there is an easy way for a DIY to pull the pan.

[tangalora]

I wonder ... since the 0-ring under the oil pan sump pickup is kinda' sqished ... is it generally recommended to replace it (I'd guess it to be a cheap part so this question may be moot) during a standard oil pan R&R procedure?

[DAEDALUS]

I was going to mention that but forgot. Definitely replace it. Why take even a .1% chance of sucking in air for the price of an o-ring?

[tangalora]

I was going to mention that, but forgot ...

Thanks. I agree it should be replaced. I was just wonderin' why it isn't mentioned as part of a normal oil pan R&R (as far as I can tell).

I mean, if we're wanting to be CERTAIN there are no chunks of chain guide around, how do we know there isn't a chunk on the upper side of that plate without specifically looking?

In hindsight, I should have baggied the oil sump sooner so as to distinguish better what was in the sump from what was in the pan & engine-bottom plate.

Also, in retrospect, what I find most intriguing is that the blue/gray RTV appeared contiguous around the oil pan.

I've since cleaned that RTV off, but the original pictures show continuity to be the case. Now that I know that front of the oil pan needs to be re-sealed after a chain-guide replacement, that's a further clue that the chain guides were never done.

In fact, I'd wager the quickest test ever of whether the lower timing cover has been removed is to twist out a single bolt of the four in the front of the oil pan to inspect the RTV color around the threads and the threaded hole.

If its red (or some other color than that unique light blue/gray), then someone's been there after the factory. Of course, this isn't a definitive test ... but it might be one of the easiest.

[DAEDALUS]

I'm kinda' sorry I didn't do a before-and-after check to see the difference in oil pressure after cleaning the sump screen of debris.

Take this lesson to heart. The diagnosis possible with the engine running is immensely more valuable than what you can learn while the car is apart. It's too easy to go with a hunch and tear into a vehicle, then wonder later about a parameter, measurement, etc. The time spent doing proper diagnosis is low-hanging fruit with a big payoff.

Can someone confirm the factory use of gray RTV on the pan? I've seen red and blue, haven't seen gray yet. Wondering if the pan hasn't been removed once already?

[911/Q45]

I'd guess the gray is 15 year faded light blue.

[s13sr20chris]

i cant say anything for infiniti but 99% of nissans come sealed up with gray rtv everywhere. rarely does the factory use anything but gray on a nissan. hope that helps some with your infiniti problem.

[Q451990]

The good news is that your oil pressure light never came on. When the car is back together with new guides, it'll certainly be getting better oil flow than before - so you will have improved things greatly. At the time you took the car apart, you weren't thinking of oil pressure or guides - so don't beat yourself up over not testing the oil pressure. I'd just rebuild it as necessary and see what you've got when your done. That's all you can do anyway!

Heath

[Q45tech]

No oil pressure light just means that the pressure probably exceeded 3psi.[switch threshold= 3 psi]. That doesn't say much when the minimum is supposed to be 14 psi at hot idle rpm.

If you ever see a flickering light it means you are way too late as all the damage has been done! But 5 psi maybe just as bad without a light indicator.

You should measure the REAL oil pressure frequently when above 150,000 miles or 7-8 years to help with your selection of oil viscosities for different seasons.

[squeefoo]

No kidding!What pompous retrospective drivel; stick to bolt calculations, and vague advice. I'm sure that was very helpful for tangalora.

I agree with Heath, we'll have to find out.

[DAEDALUS]

No kidding!What pompous retrospective drivel; stick to bolt calculations, and vague advice. I'm sure that was very helpful for tangalora.

It may not help on this particular task, but it is a good lesson for future work. You may not think it's good advice, but I do, as would most techs. If you have a problem with me personally then email me. Keep your pisspoor attitude out of my forum.

[mixatonia]

It may not help on this particular task, but it is a good lesson for future work.

Yes Yes Yes Yes YesThe best about reading these really good interestng discussions is the lessons for future works. For that reason alone its probbly good to question everything.

hind sight for you is future sight for me

Keeep lessons coming!!!!!!!!!!!!!!!

[Cdon851]

On the usenet rec.autos.tech a bunch of people are posting a reference to this oil pan forum but one thing I noticed is you never summarized the procedure.

It is obvious you did the procedure with the help of many technicians and owners but its not obvious how you got there in the end.

Are you going to summrize the dos and don'ts for us and for all the new people coming on from references on the usenet?

[tangalora]

Right now, I have a half dozen roughly scribbled-upon pages on the back side of a by-now well grease stained NICO printout of the previously reported oilpan R&R steps (which turned out to be totally wrong in some instances).

I also froze every single step in a photo (more than a thousand) in case we need to revisit anything in detail (and so I can put the whole thing back together when the chain guides are done).

Since all the previously documented reported guides turned out to either be missing key steps, or to be downright wrong (e.g., remove alternator, remove rear engine gusset, etc.), I think I'd be writing the very first known Q45 oil pan R&R detailed howto.

This takes time (so please be patient). I may never have time to include all the photos (this happened with my fuel pump R&R, my sunvisor R&R, my 4-wheel brake job R&R, my radiator R&R, etc., and so it may be with the oil pan & chain guide R&R ... but in all cases I promise to at least submit the complete steps in pure text format (which I've done for all the others too).

Someday ... sigh ... I'll spend the five or six continuous hours to write up a complete article with step-by-step photos (you guys deserve it) ... till then, we'll all have to do with these well annotated questions & answers (which cover the topic rather well but they skip the easy steps which didn't have questions).


Modified by tangalora at 12:27 AM 12/18/2004

[AlabamaDan]

I think we all have grease stained NICO printouts in our toolboxes.

[911/Q45]

Anyone heard what's up with Tangalora's project?

[maxnix]

No, but in reviewing the posts, I think it is fortunate she hit her oil pan.

Maybe I'll swing by on my farewell to the left coast tour in a week or so. Isn't she not that far from SLO?

[911/Q45]

I think she's in Sacramento, but understandably reluctant to share her exact location. That is about 300 miles from SLO. You're welcome to stop by here on your tour.

[maxnix]

I think she's in Sacramento, but understandably reluctant to share her exact location. That is about 300 miles from SLO. You're welcome to stop by here on your tour.

Love to see your cars, so I might well do that. Can you email me a contact number as I won't have internet access?

Sacramento may be correct as there are a dearth of technicians there from what I can remember.

[louiegz]

Just wondering. Is Tang's car fixed yet? Anyone knows?

[jrfryoux]

Did this work for you, I have 1995 Q45 Just bottomed out oil pan has a small hole it needs to be re[placed. Please Email answer to [email protected]

[96Qowner]

Tangalora is gone and sorely missed. It did work for her.

It's a big job. A couple members have merely patched the pan, if it's just a hole and there's no danger of the oil pickup area being damaged.

[jrfryoux]

Thanks,

It is just at the front of pan small hole no damage to pickup area. What would be a suitable patch?

[96Qowner]

Um .... (they're gonna kill me) ... how 'bout some JB Weld?

I've heard it works wonders in these situations.

[goody90q45]

Um .... (they're gonna kill me) ... how 'bout some JB Weld?

I punctured my oil pan last year just above the drain plug. JB weld has held up just fine. Use the JB that takes 24 hours to cure not the 4 hour quick weld.

[maxnix]

Bump for sticky status, or at least an article.

We miss you Tangalora.