3.0L Burning / Leaking Oil Repair Guide

05-28-2008, 02:08 AM
Hi everybody! Does your 3.0L V6 leak or burn oil? Well I've got a simple guide for the complicated process of correcting those problems. Although, this guide is much more for the burning problem. My LeBaron's 3.0L got cracked head gaskets at 170,000 miles, and started burning oil, probably because of the antifreeze in the oil. You might think, what do head gaskets have to do with burning oil? Well, the cheap way of correcting oil burning is to change the valve guide seals with the heads still on the engine, while you constantly worry about your valves falling into your cylinders. Plus, if you're burning oil, chances are your head gaskets will be due for changing very soon anyway.

Things to note: An engine that has been burning oil for a long time may seize and/or blow if you fix the oil leaking into the cylinders. And an engine that has been leaking oil may have screwed up bearings if the oil level has not been maintained.

Things you need:
-Wrenches, metric and American, long, medium, and short.
-3/8 inch drive ratchet
-Torque wrench
-Sockets, 3/8 inch drive, metric and American, shallow and deep,
-Swivel sockets, 3/8 inch drive, if you have them, you may be able to work without them.
-Extensions, 3/8 inch drive, long and short.
-Pliers, vice-grips, needle-nose pliers, wire cutters.
-1/2 inch drive impact wrench (air gun)
-Some 1/2 inch drive sockets (21mm, 3/4", 18mm, etc)
-1/2 inch drive breaker bar or wrench and a piece of iron pipe to turn the main pully
-Pry bars/crowbars
-Heavy Hammer
-Propane torch (may need this)
-One of those polishers to clean the engine block
-Other tools as needed
-General knowledge of mechanics
-Common sense

Parts to buy:
-Head gasket kit, which should include head gaskets, valve guide seals, cam seals, valve cover gaskets, intake and exhaust manifold gaskets, and some other stuff I'm probably forgetting.
-Intake plenum gasket kit.
-Can of gasket spray adhesive.
-New spark plugs and wires, maybe cap and rotor if you need them.
-Front main seal.
-Gasket Shellac (NAPA makes one called Indian Head Glue)
-Valve grinding compound.
-Repair sleeves for seals, if you can get them.
-Timing belt.
-Other stuff as you need it.

Rough idea: take your heads off, do a valve job, replace a whole bunch of oil seals, put back together. I'm trying to make this guide as short as possible for people who can figure out the details on the job instead of following a really long step by step guide.

-Start by disconnecting your battery of course.
-Disassemble the whole air intake system.
-Drain the antifreeze.
-Remove the intake plenum and manifold.
-Remove the valve covers.
-Remove the front exhaust manifold.
-Lift up the car and put it on jack stands.
-Disconnect the rear exhaust manifold from the exhaust pipe that goes to the catalytic converter.
-Remove the passenger side tire and the plastic behind it, that covers the belt pulleys.
-Disconnect the two gas lines that go from the body to the engine.
-Dissassemble the front (passenger side) of the engine. You will have to support the engine from the bottom, with a jack and a block of wood. You need to take off the motor mount to disassemble the front of the engine. You'll have to disconnect the gas lines there. They my be rotten by now unless they have been replaced before, you may wish to change them. They unplug by pushing the plastic part upwards, or into the metal part of the hose.
-When you get the timing belt exposed, remove the main pulley via the 6 little 10mm screws, set the timing to zero by turning the engine, from the main pulley, clockwise until the timing marks on the two cam pulleys and the main pulley line up with their respective timing marks. Remove the main pulley bolt with an impact wrench, pry off the pulley. Remove the belt, the cam pulleys may snap out of place, ignore it for now. Gently pry off the main timing belt pulley, it should slide off, but you may have to torch it, prying it too hard will damage it, or the oil pump, easily.
-Remove the cam pulleys.
-Remove the distributer.
-Remove the heads, the back one will have the exhaust manifold on it when it comes out.
-Remove the front main seal.
-Take your heads apart, make sure they are not cracked anywhere, then take them to a machine shop to be "machined" - they are aluminum and warp when you take them off, they need to be shaved down to make a perfectly flat surface for the new gaskets.
-Do a valve job, look for another guide on doing this, you'll need that valve grinding compound. While doing the valve job, replace the valve guide seals, they are right where the valve stems go through the heads, these are what commonly leak oil into the cylinders, causing oil burning and blue smoking. Use a pair of pliers to twist them off.
-Replace the front main seal and cam seals, you will need a certain kind of glue to put around the outside of the seals. It's called gasket shellac. If you can find them, get "repair sleeves" for the front main seal and cam seals. These are thin metal sleeves that fit around the cams and crankshaft, to give them a new surface for the seals.
-Clean everything, the top of the engine block, the front of it, scrape the head gaskets off of the block and the heads, use the polisher to clean the engine block to make a clean surface for the new gaskets. Your head surfaces should be shiny and clean from the machine shop. Feel each of the pistons for side-to-side play, hopefully there will be almost no play at all, otherwise, your piston rings are screwed.
-Make sure your block and head surfaces are clean and dust free immediately before installing the heads. I recommend using a spray can of brake parts cleaner to wash off all of the surfaces. This stuff is mostly alcohol so it cleans well and dries fast.
-Put your heads back on, with new head gaskets, of course. Thread all the bolts in by hand. Now you need a torque chart to tell you exactly how much torque to use, and it should also give you the order in which you tighten the bolts, this is *IMPORTANT.* Now screw in all the bolts until they stop, but they are not tight. Use your torque wrench to tighten the bolts (in the specific order given by the torque table) in 10 or 20 lb-ft increments. So basically tighten all the bolts, in order, to 10 lb-ft, then start again, but with 20 lb-ft, then so on.
-Reassemble your engine with new parts! Do a tuneup while you're at it. Make sure the timing is correct. Although the 3.0L V6 is a non-interference engine, there is still the off-chance that you may bend your valves. Besides, it wont run right, or at all, if the timing is off.
-You might want to do an oil change now, since you may have gotten dirt, metal particles, brake cleaner, and antifreeze in your oil.
-Voila! Now you have a semi-rebuilt engine with a tuneup and new seals.

Estimated cost (I didn't keep exact figures): $250 USD

I didn't see any guides here about these very common problems (burning oil, leaking oil, and cracked head gaskets), so here it is. :grinyes:

And yes, a head job may be a bit complicated for just leaky valve guide seals. But like I said, if a valve falls into the cylinder you'll have to do a head job ANYWAY. Plus, these engines are all going to be in the upper 100k miles area if they are burning oil, and will soon need heavy duty maintenance like this anyway. And if you want to only replace the valve seals, you're going to do *ALL* of this work anyway, except removing the heads, so you might as well just do it while you're there. On the other hand, if you're not burning, just leaking oil, just ignore the instructions pertaining to the heads, so only the front of the engine needs to come apart.

05-31-2008, 12:31 AM
Whoa... that's a lot of work..! I used to replace valve seals on my old audi's and the oil burning would slow or stop. A 4 cyl is about 1/2 the work too.

A test for the valve seals is this: at a higher speed, use the engine to brake (with an auto, shft down to 3) for 10 sec or so, then get on the gas lightly. If you see a huge cloud of smoke appear, you've sucked oil past the valve seals, down the guides and into the intake (while under a high vacuum). The oil is just sitting there on the valve and when you open the throttle whoosh - it burns into smoke. I used to do this on purpose to off-ramp tailgaters in my Scirocco, whenever possible. Never underestimate the huge cloud of smelly smoke that can come out of a tiny little car.

The seals alone can be changed relatively easily but like all things in life, the proper tools must be used. A valve spring compressor and spark plug fitting to hold the valves UP with air pressure helps.

With these vehicles so plentiful and cheap, if you can quickly fix common minor problems, you'll always have cheap wheels. My 91 Caravan has 200 k mi on the 3.3 and I paid $250 for it 3 years ago. I just can't bear to part with it as it's fully loaded, and everything works flawlessly. I customized it with metalflake (super-sparkley) paint.

I am currently looking for a fake supercharger (or I will make one) to stick on the hood. The bigger - the better - and the hood slopes downward so it won't interfere with vision (safety first..!) A realistic-looking chromed-plastic V8 blower... Most blown (show) cars look almost surrealistic, so unique looking and shiny. Like something you'd see in CARtoons magazine (is that still published?) Now that would look cool. Especially if the pulley/belt turned (ala Road Warrior). With a "Vroom-box" for realistic engine sounds and some undermounted waterproof subs, the effect could be VERY cool. Blown V8 Caravan... coooool...

Downside is that every 17 year old and geezer in an INFINITI would want to race me. But I'm old enough to resist that urge, it is a minivan after all...

06-04-2008, 04:10 PM
lol you sure like shiny stuff! (Who doesn't?) And blue smoking can indeed be very useful for tailgaters. In fact, I've been working on a way to make my car blue smoke at the touch of a button. Perhaps somehow put oil into the fuel rail with an electrically powered valve?

Oh and speaking of racing, I can't tell you how many pricks in broke-down old toyotas and hondas with coffee-can mufflers, spinner hub cabs, and stick-on chrome trim have tried to race me at red lights and lost miserably. My LeBaron is all stock, basically, but it still easily beats those losers who think they got something with their crappy old wannabe riceburners. And yes, Chryslers are plentiful and cheap. Love 'em.

And yes, I know about this using air pressure to keep the valves up, so you don't have to take off the heads. I was wondering about that, why couldn't you just turn the crankshaft so the piston in the cylinder you're working on is all the way up, like at the end of the exhaust phase? Then the valves would simply fall slightly to stop on the piston, wouldn't that work? But anyway, my point is, when changing the valve guide seals only, without removing the heads... you're SO close to doing a valve job AND replacing the head gaskets, and at 100,000+ miles, you might as well do it since you are going to have to take off the whole front of the engine to take off the timing belt, and the whole top of the engine to open up the valve covers, the only thing left it taking off the heads.

06-04-2008, 08:37 PM
lol you sure like shiny stuff! (Who doesn't?)

Vehicles are so drab these days. The odd red car, but it's all dull colours these days. And very little chrome - unless you drive a Crapillac EscaLame. I suspect chrome is about to make a comeback... except it will be silver or aluminum on plastic with clear coat (see the Cosmic Chrome process - it is amazing)

I liked the 70's colours, I have a bright green Renault - remember the Dodge 'sublime'? Just like that. And someone is selling a Citroen DS, as well as an Opel GT. Bright yellow - WOW! I am seriously thinking of them both. I know, I'm insane. A yellow Citroen with the plate - "LEMON"... too cool (am i weird?)

The colour shifting metalflake powder is available on ebay (paint with pearl) super cheap and you just add it to some clear. Amazing stuff. And shiny.

ANyways - back on topic. I usually don't fix anything on my old chaep vehicles until something breaks. So I always have a spare vehicle 'at the ready' for it always happens at the most inopportune time. But they usually give a bit of warning first, like smoke, oil consumption, odd noises etc.

06-20-2008, 02:18 AM
This is true, car colors have gotten a bit drab. But I think the future is looking up. Chrome IS making a comeback, but yes, it's plastic chrome. However, the chrome that IS "in" is extremely shiny, so that's a good thing :P. And colors are getting better, instead of gray, we have shiny silver, and vibrant blues, yellows, reds, etc. You know... I haven't really seen any new white cars... is white going out? BTW... you must live in europe with your silly opels and citroens and renaults. Thank goodness the french are scared of the american car market ever since the amc thing with renault. Even if opel is "German" *cough* GM *cough*

Back on topic, well I look at it this way, I'm putting about $300 into my car and I'll be getting at least (hopefully) another 175,000 miles out of it, for slightly less money than buying another one. No to mention that my LeBaron was somewhat well-kept, seeing as how it lasted 175,000 miles with no blue smoke, it only started blue smoking AFTER it got anitfreeze in the oil, which I am guessing ruined the valve seals. You know, in a few more years, I may be one of the only people left who own a 3.0L V6 that's not blue smoking.

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