1993 D21 V6 4X4 Questions

[digs]

I have a 1993 D21 v6 4x4 that recently had the ABS and brake lights come on. They turn off when I turn left and back on when I turn right. I think it may be low brake fluid. I will check and report back. I saw another thread about this topic on this site but there was no stated resolution.

Another question I have is about the tach. It doesn't read properly 95% of the time. It just kind of bounces all over the place. Most of them it reads extremely high. Suggestions?

The next problem I have is more difficult to diagnose. There has been a mid pitch "straining" sound on the engine for a while now. Sometimes it is even kind of a grindy souding skreetch along with the whinning strain. It is worse when it is cold and less obvious but still there when it is warm. The harder it is driven, regardless of weather, the worse it gets most of the time. When I come to an idle after running it hard, the sound is very noticeable. Some of it just sounds like it is straining to get air, other times it sounds like a pulley or something. I am only a shade tree mechanic.

I have, changed the plugs, the cap and rotor and spark plug wires. I have a new k&n air filter and large battery. I have replaced the catalytic converter with a straight piece of exhaust pipe, (this helped some). I ran some 44k though it a while back before the issue after I had the new plugs, cap & rotor and wires installed.

The final question I have is about a small oil leak. It really isn't enough to worry about even over a 3k mile oil change interval. However, it is there. I am 95% sure it is leaking out of the main seal. Last oil change over the weekend included a bottle of lucas. 1) How can I be sure where the leak is coming from? 2) If it is the main seal... could the be tackled at home and/or how much would it cost to have a shop do it (about). I live in Colorado.

[AZhitman]

Welcome aboard! Love the D21 4x4s, such a great, durable truck.

RE: brake/ABS lights, check fluid, but also check your wires to both front brakes - if there's a loose connection, that'd cause the same issue. You may want to have the front on stands, wheels off, truck running, and have someone move the cables while you watch the dash for lights.

Tach - Common issue on those is an electrolytic capacitor on the tach circuit board that leaks. Not too hard to fix, if you pull the gauge cluster and solder in a replacement.

Screech - Listen for it with the hood up and see if you can pinpoint it a little better. Is yours a manual? If so, you may have a throwout bearing going away. Otherwise, it could be a lot of things, but most likely a bad pulley bearing (water pump, power steering, etc).

Leak - Best way to trace a leak is with a dye kit (about $15). Clean the underside of the engine thoroughly (pressure washer and degreaser). Add the dye to the oil, and run the engine up to operating temp. Crawl under there (best in the dark) with your UV light and find the glowing - it'll be very obvious, like neon. There's your leak.

If it's a rear main seal, you're looking at a pretty big job (best done with clutch and throwout bearing repair). Front seal, also a big job, best done with water pump and timing belt job. Oil pan, pretty simple. ALL of this can be done by a shadetree mech - We have the factory service manuals here for you, and if you take your time and follow the steps, you'll nail it.

Hope that helps - Keep us posted!

[digs]

Brake: Topping off the reservoir worked like a charm. Lights went off immediately. Strange to me that it was half way in-between the min and max line but it caused this issue. I am thinking of replacing at least the passenger side caliper - looks to be about $50 from Napa. I know that one has a very slow leak.

Tach: I am adept at soldering, where can I get this capacitor if this is the issue and how do I get to the gauge cluster?

Screech: I am fairly certain the sound is coming from the front of the engine, so probably not a throw out bearing. It is a manual though. How do you pinpoint a sound like this and narrow it down to one of the pulleys?

Leak: I did check the oil pan, nothing there. Oil definitely comes from rear of the engine. I will do the dye after the snow melts this spring or I can bring it into the warehouse at my work.

Thank you very much for the detailed response.

[AZhitman]

Glad to help, that's why we're here.

Once you pull the cluster out (info in the FSM linked below), there'll be a code on the capacitor - most electronics stores should have it... most likely less than $1.

Pinpointing sounds is tough, but two people (one to fluctuate the throttle, another to move around and look under the hood while making funny faces) can usually get pretty close. If it's from the front, it's either a PS pulley, water pump, or alternator - I don't think the D21 has a separate tensioner.

Here's what you're looking for: www.nissanservicemanuals.com - Easy to navigate through to your truck.

Keep us posted?

[digs]

I changed out the idler pulley for the AC belt and everything now sounds normal. Easy 5 minute $25 fix.

Now on to the tach and leak.