New guy, with new old q45

[Haitian_King]

Glenn,

You didn't buy Matt's diff did you? If you did, congrats. I was looking into buying it.

[maxnix]

Do both valve covers at once while you are there. Plugs?

Replace the tensioners and strongly consider the oil pump chain.

The main thing is if the timing has not skipped, use the qip ties to hold the chains in tension on the camshaft sprockets. Next is if you have peices, account to all of each guide by putting it back together so you know no pieces are in the sump.

You can do it, but you will need a good torque wrench, and coolant. Might wat to replace your thermostat and pressure cap also.

[Haitian_King]

I thought about plugs. I'm at 90,307 (as I type this). Do they need replacing now? I don't think I have a torque wrench. I need to buy one. I have to drain the radiator before I tke it out right? And refill it after install? Do I need to drain engine oil too? After reading the write-ups, I added the timing chain and oil chain to the parts list because of the the stretching of the old ones. How do I know if it's jumped time? It's been running well. I'm starting to notice a little roughness in the idle again so I'm suspecting another injector. I need to get a voltmeter to ohm them. I have three good injectors to use. I hope it's an easy one like the #1 or 2.

When doing valve covers, what needs to be done? I've been searching, but I can't really find the info I need. Hopefully I can find a write up.

Thermostat and pressure cap need to be replaced? Hopefully, the guide job is successful. After that's done, I'll get my oil changed and have the mechanic drop the pan and check for pieces.

Thanks for the advice.

[oldmako]

I have NOT done much work on this thing since I've only owned it a month so take the following with a grain of salt....

With regard tot he valve covers, it's POSSIBLE that they only need to be re-torqued and the old gaskets are still capable of keeping the oil in. Over the years I've fixed "leaks" on many old cars and boats (valve covers, oil pans, dip stick tube mounts etc) by simply tightening the bolts around the offending unit. Follow the correct sequence, and use a TW if you have one.

These engines get hot. Multiply that by thousands of trips over the years and stuff loosens. I plan on simply snugging the bolts on mine, then cleaning it up well. If it continues to leak, then I'll replace the gaskets. The dealer gave me an outrageous quote to replace them, so I imagine it's a fairly big job on this engine. I don't see or smell any leaks, so there's no way I'm going to just part with $600.

For what it's worth.

[Haitian_King]

I've been smelling something that I always just assumed was "hot engine". Keith told me that he can smell the burning fluid (Oil? Coolant?) I haven't noticed any leaks on the ground, but if I'm burning oil, I'd like to stop it. It's been 15 years. Do the covers need to be resealed? What's the deal on it? Just RTV? Or is there an actual gasket? It'll be easy to do with the front cover off right?

As I'm typing this, I'm reading Tangalora's post on replacing the oil pan. If my mechanic wants to do all of the things that need to be done and in the span of a weekend (Friday-Monday morning), I'll gladly pay him the goodly sum of $1000 dollars (or less if it calls for it.) If I supply the parts and he does the labor, I can get that grand to stretch a long long way. Once my VH is taken care of, I can nail down the transmission and have a perfectly running Q and be ready for cosmetics by June. Yay!
Modified by Haitian_King at 11:16 AM 1/9/2008

[GseaQ]

No, our '95 came with a 4.08 and we're re-installing the original.

[GseaQ]

HK,

You will need plugs - overdue already.

You will not need a timing chain - a lot of extra money, time and risk of getting something wrong in timing a new chain. The original chain is good for at least 300,000 miles. The general stretch trend is that by about 90,000-100,000 miles the stretch has happened and is really unlikely to continue. At that time get your timing re-adjusted via the CAS. We did that over 100,000 miles ago and the timing is still good.

Do replace the oil pump chain AND oil pump chain sprockets. The teeth wear. No need to drain engine oil or remove the oil pan unless guide pieces are missing.

Valve (cam) covers need re-sealing on all these engines by now. The '90-'93 use RTV sealant and half-moon end plugs and the '94-'96 use rubber gaskets and end plugs. They will leak oil onto the exhaust manifolds which then burns off before it can drip onto the ground until the leak turns into a gusher.

[maxnix]

With regard to the valve covers, it's POSSIBLE that they only need to be re-torqued and the old gaskets are still capable of keeping the oil in.

No, that is a real bad idea! The covers leak because the RTV or rubber has lost its elasticity so will not seal any longer.

Over torquing an aluminum reciever is a very bad idea unless you love helicoil.

These engines are not Detroit cast pig iron!

[Haitian_King]

Maxnix,

What's helicoil?

Glenn,

Thanks for the info on valve covers. So I just take mine off, clean the mating surfaces and apply a new layer of RTV? What about these half-moon end plugs? Where do those come in? Plugs don't need anything special right? Just take out the old and put in some new Platinum NGK's? IIRC no plenum removal right? How do I retime using the CAS? For that matter, how can I tell if the timing has jumped a tooth?

So that's why I've never noticed oil leaks, but I did smell it. Ok. Will do.

[yodawill2000]

A helicoil is what you have to use if you strip out the Aluminum from over torquing.

[Haitian_King]

Thanks. I'll Google it. Hopefull I don't end up having to need one.

How are you liking your J30? I was out with my friend who used to have a '94 J30t. He was telling me how much he loved it. We used to do so much racing in that car.

[GseaQ]

OK HK,

You need to buy new half-moon end plugs from Joe. The originals get hard and leak.

Make sure you check the gap in your spark plugs before you install them. Don't bother getting the colder than stock plugs. The standard is fine unless you live at the race track and even then I'm sure they'd be fine.

The CAS is used to set the base timing of 15* BTDC. As the timing chain stretches, the base timing will change a bit.

Glenn

[SATAN]

I am willing to put money on the fact that if the chain has not jumped already, it is not going to jump while doing a compression test. It is a game of chance. Chance is HUGELY on my side. I bought the car assuming that worst case scenario, it needed a new engine, which is fine. Its NOT a big deal.

But... either way, I will get a mirror and check the guides to see if they have been replaced. IF THEY HAVE, then I will put it back together, get a new CAS from someone and see if it starts, If not, I will pull it apart and see if it has jumped teeth or if it is timed correctly.

I will play it safe and not crank it anymore until I know for sure. Are the guides an Infinity only thing or is there someone here that sells them for cheaper than Infinity would?

[GseaQ]

The guide stuff is dealer only, BUT Joe at Infinity of Scottsdale (InfinitiPartsUSA.com) gives club members great discounts and may even have a "kit" he can put together for this job.

[maxnix]

I am willing to put money on the fact that if the chain has not jumped already, it is not going to jump while doing a compression test. It is a game of chance. Chance is HUGELY on my side.

And you could be fatally wrong. Chance is actually hugely against you.

But as Harry Callahan said, "Do you feel lucky, punk?"

Don't be one. Inspect the timing chain guides first, then do your compression check. We are trying to help you. Why take a chance that is unnecessary?

[Haitian_King]

We are trying to help you. Why take a chance that is unnecessary?

Quite true. The last thing any board member wants to see is another owner taking unnecessary risks. I've been reading archived posts and I've learned that these guys have been learning the hard way about Q's since the Yahoo days. They know what they're talking about. They've been there and done that. Probably why they're so fashionably jaded. To quote the Barenaked Ladies: "It's All Been Done."

[brooklyn_in_kansas_city]

a i just got a 1990 Infinity q45 and i know what i need but it like no one have it in stock. Do you know of any sits that i could buy a ignition lock cylinder,a hood, hood latch, doors locks and a trunk lock.....anyone

[Denver90Q]

But... either way, I will get a mirror and check the guides to see if they have been replaced. IF THEY HAVE, then I will put it back together, get a new CAS from someone and see if it starts, If not, I will pull it apart and see if it has jumped teeth or if it is timed correctly. ?

Probaby won't see much with a mirror but you may be able to get a fiber optic scope down there.

[Haitian_King]

Check infinitipartsusa.com. You car rebuild your whole car from there.

[GseaQ]

You should be able to see if the guides are metal backed or not.

[96Qowner]

a i just got a 1990 Infinity q45 and i know what i need but it like no one have it in stock. Do you know of any sits that i could buy a ignition lock cylinder,a hood, hood latch, doors locks and a trunk lock.....anyone

Check NICO's Infiniti Parts Forum:

zeroforum/172

Several members are parting cars.

Also http://www.car-part.com ... a national search site for salvage yards.

[maxnix]

Make sure you check the gap in your spark plugs before you install them.

Don't bother getting the colder than stock plugs.

Actually, the 11 in th plug specification refers to the 1.1 mm gap.

Do not measure or change it unless you have a professional gapping tool that will keep the electrodes parallel.

In TX and AZ, some of us run the colder 6 heat range which was the original plug heat range specification.

[maxnix]

I've been reading archived posts and I've learned that these guys have been learning the hard way about Q's since the Yahoo days. They know what they're talking about. They've been there and done that. Probably why they're so fashionably jaded.

Good for you! It's amazing what one can learn from these earlier posts. A couple of years ago, the first thing a new member would do is sit down over the course of a month or two and read these posts. There was a lot less "Which Dubs should I get?" or "You've got mail." type of posts back then.

Still, why I encourage every new board member to read all of Q45tech's posts for starters (and follow his links) and TexasOil's if one has an active. Most of the other solid informational posts are contained within these threads.

Spread the Gospel of the Q45 according to Dennis, please.

[Haitian_King]

I try to understand Dennis' posts, but some of them are just way over my head. I spent a couple of hourse reading Tangalora's oil pan replacement. I'm feeling much more confident in Q mechanics. I actually chuckled at some of her posts. She wrote quite well.

[maxnix]

Dennis' prose is kind of a cryptic post-apocalytic crisis engineering style.

It's like reading Chaucer in the original. After a while, your mind accomodates and completes and corrects the narrative and declarative sentence structure. The facts are all there for those who want them.

[oldmako]

Who said anything about over tightening the bolts? I merely suggested that perhaps they had come loose. If they are already tight, then certainly the gasket /seal is bad and they need to be replaced.

No, that is a real bad idea! The covers leak because the RTV or rubber has lost its elasticity so will not seal any longer.

Over torquing an aluminum reciever is a very bad idea unless you love helicoil.

These engines are not Detroit cast pig iron!

[maxnix]

Who said anything about over tightening the bolts? I merely suggested that perhaps they had come loose.

They generally don't (aluminum is ductile and frictive), and there is so little margin in an aluminum reciever and with no elasticity in the gasket there is a danger of stripping them torquing them even at OEM specifications.

When the rubber is gone, it's gone. Even on old brittle hoses, an extra turn on the clamp will only buy you a little time, if any.

[SATAN]

And you could be fatally wrong. Chance is actually hugely against you.

But as Harry Callahan said, "Do you feel lucky, punk?"

Don't be one. Inspect the timing chain guides first, then do your compression check. We are trying to help you. Why take a chance that is unnecessary?

You are telling me that out of the 160,000+ miles this car has on it and chain hasn't jumped yet, that the next few cranks it "is hugely against" me? I'm sorry but that statistically impossible. That is like million+ to one odds FOR me.

Perhaps you didnt read my whole post, I AM HEEDING the advice and inspecting the chains before I do anymore cranking though. I will probably get to it this weekend. By the time I get home on the week nights it is too dark to do anything. That and one of my other cars just got totaled out by some other person, so I have been dealing with that this week too.

I do appreciate the advice of the board members. Thank you for replying.

[Haitian_King]

Hmm. Good point.

The thing about these chain guides is that they don't really have a set time to go kaput. Some guides have gone well before 100k and others have gone beyond 100k before being replaced and were still intact. Maybe it depends on karma?

Aww man. What happened to your other car? Is it really bad?

[maxnix]

You are telling me that out of the 160,000+ miles this car has on it and chain hasn't jumped yet, that the next few cranks it "is hugely against" me? I'm sorry but that statistically impossible.

Actually, statistics has nothing to do with predicting an individual event, only its likely hood presuming the data collection desgn and analysis was done correctly.

You missed the point that the stress on the timing chain and thus the guides peaks at intial crank on a cold engine.

A few too many others who knew exactly what you know now wish they had not.

Why take a risk you don't have to take? That is the fundamental question. It is an absolute risk you can avoid.