What happens to oil after 4 years in an engine?

I will preface this by asking that no rude comments towards the owner of this vehicle be made. This post is intended to educate.

A customer brought in their 1999 Tacoma Pre-runner with a 3.4 V6 engine. they had just bought it and knew the initial condition of the engine was questionable. The timing belt was broken and there was no way to check the condition of the engine at that point. The purchaser was also told that the truck had sat up for 4 years since the belt broke.

It was towed to our shop and left with us to inspect and check the condition of the engine. Using a HAND TOOL, the crankshaft was checked and free movement was noticed. The camshafts were also checked for freedom of movement, and all of them checked clear. The problem was noted when the water pump pulley was seized up, as well as the idler pulley for the timing belt. It is my belief that the water pump seized, causing the belt to break. However since 4 years has lapsed, there was no way to tell for sure, and no belt burns were noticed on the water pump due to the rust.



Thanks to a previous vehicle recently being in here for a new timing belt and water pump kit, I had a spare backup belt, water pump, and pulley set. I set the crankshaft and camshafts to the correct timing mark, and installed the donor parts. Since this engine is a zero-clearance engine, the only way to safely get the crankshaft and camshafts lined up properly was to be VERY slow and careful when rotating the parts. The first step is to get the crankshaft to TDC of the #1 compression stroke. Once there I backed off the crankshaft about 30 degrees. This allows the camshafts to safely rotate without any of the pistons striking an open valve. After the crankshaft was set and backed off, I rotated the cams to their proper timing mark, and returned the crankshaft to the proper position. I then installed the water pump, pulleys, and belt. (Note that these photos are from a different truck, and are just visually indicating a properly set up timing belt)

If you notice on the single cam pulley photo, it is stamped as right or left pulley. You CAN install them incorrectly, so watch how they come off and go back on. The "L" or left pulley goes on the left cylinder head, NOT on the left side as you look at the engine!









Since we are concerned about the engine already being damaged, we hand rotated the engine and I noticed at 4 different points that there appeared to be minimal, but definite contact of valve and piston. This was further diagnosed with a cylinder leakdown test showing that the left head had 2 cylinders that would not hold any pressure. Time for the heads to come off.

Removed the valve covers, and you can see what 4 years of oil sitting inside and engine can do. It did not look pretty. Once I removed the heads I noted that on the left head, 3 different valves in 2 different cylinder heads were stuck open. The appearance was that they were bent, however further inspection showed that they were stuck in their bore. Either way, the heads needed removal, as you could also see a large amount of carbon buildup on the pistons. This carbon was so dense that the chunks almost appeared to be a broken piece of the engine. The photos do not show up very well however. After the heads were removed, the oil pan comes next. This REALLY shows how bad oil can get when sitting for an extended period of time. 4 years is a long time. The oil itself was actually SOLID, and would not even move when the pan was stood on it's side, or even when INVERTED!

The good news was that the cylinder walls were free of scoring, and still were in good condition.















The next pictures show what happens after 4 days of vat soaking, and two vats of fresh fluid will do to said cylinder heads. We are currently waiting on parts, and we will do what we can to show a step by step assembly of the heads, and the timing. For those who are curious, even though the engine say for 4 years, it appears that the oil in the crankshaft journals had drained down into the pan, thus not clogging up the crank bearings or rod bearings. At this time, due to the cost, the customer has decided to take the chance and just clean what we can, instead of totally disassembling the engine and rebuilding.

 

Hmm

 

That black sludge deposit is also how it looks after the oil has not been changed often enough when using dino oil. I hate cleaning that stuff. I have replaced a lot of Toyota 3.0L short blocks that were black with sludge like that.

 

*runs out the door to change oil*

 

Yes, they do look the same way if the oil is not changed regularly. However I do not think that is the case here. Oil sitting for 4 years inside a dormant engine will do the same thing.

It really depends. This engine shows no signs of complete failure at all. It is quite rebuildable on it's own. However the cost of a total rebuild is QUITE expensive on these engines. The Mitchell1 labor time guide shows 25 hours minimum. At an average labor rate of $80 per hour, you are looking at @2000 just in labor alone, plus the cost of the parts. The owner took quite some time in deliberation over all options. One option was a new engine, another was a salvaged engine, then there was a total rebuild option, and then there was the option to proceed as we are, and replace the head gaskets, rebuild the heads totally, and then clean out the oil passages in the block. As it sits right now, the owner is looking at less than $2000 for the entire repair.

 

I'm curious about this..let's say I was planning to store my vehicle for 4 years. In terms of the engine oil alone, what would your best advice be to me? Assume that it's not an option to start and run the engine.

Regarding this particular vehicle..what would the ballpark price be for a new engine or a used one, and to remove and replace in both cases? Assume you can find the exact same engine new or in a donor vehicle.

 

Hi,
Im the owner of "Sludgenstein". Bill has been very forthcoming about all of the options/risks, etc. At the current time, I believe that the engine will run as new when Bill gets through with it. If not, i will have an expensive boat anchor and Bill will have some of my $ to spend on his Tacoma!

I truly believe that the previous owner never changed the oil in the 80k miles that he owned it (I know him).
So:

old oil
+4 years of dormant oil
+ cheap oil
-----------
the pics that you see above.

In case you have never met Bill,
here is his picture

 

If you are going to store your vehicle for 4 years, I would recommend changing the oil and using synthetic. Run it for a few days before storage. The synthetics handle aging much better than dino.

As for installing a new/salvaged engine, the labor time shows 13.2 hours to swap out a salvaged engine. If replacing with a new engine (i.e. longblock) then you would be looking at approximately 15.5 hours. Multiply that by the average labor rate in MA of $101.00 per hour and you are looking at either $1333 or $1565 in labor, plus the cost of the engine.

You little shit! LMFAO

Of course you know that you are now stuck with your own name. From this point on your Tacoma shall be now known as SLUDGENSTEIN!

 

My first job in this country was a Lotus dealer in National City Ca. Car washer.
One day this old lady maybe 80 years old come in to buy a $85000.00 Lotus Exprit and insisted to have her (Good looking) Mercedes traded in. Because our mechanic was in lunch, my boss told me to take a look at the trade in car. It was running good, the transmission was shifting nice etc. I turned the engine off, opened the hood and try to check the oil. The dipstick was clean and had no trace of oil. I told that to my boss and he proceed to ask the lady, when she changed the oil last time. Oil, what oil, nobody told me to change any oil. Turned out her husband died 3 years earlier and forget to mention. She ended up buying the Lotus with out her trade in, and I dump 2 quarts of oil in her engine and hopefully she learn about the oil change.

 

I am surprised that in 3 years she hadn't burned through all of the old oil!

 

Did you happen to see if the guides are cracked or mis shaped from the possibly bent valves?

 

That motor in way nasty. Just a visual as to why oil changes are important. Also, I have always been under the impression and understanding the these motors were non-interference motors. I noticed you stated in the op that it is a zero clearance engine. Quick search showed this. Just curious http://www.tacomaworld.com/forum/1st-gen-tacomas/94527-non-interference-motor-3-4-a.html

 

I see no problem for a clean engine to sit with clean oil for a few years...My Town Wagon, with a rebuilt /6 motor is sitting waiting for some body work and a new gas tank...the oil is still clear and full after a four years of sitting. I am sure it will start with gas and a fresh battery.

On the other hand, a motor that was stored in poor condition will degrade into worse condition

I have a buddy who specializes in Jeeps that have been abandoned. Usually they have been run hot, then parked for a few years. Pulling the head and pan is usually required.

Howard

 

As always, BamaToy..explanation I don't need a dictionary to read and answers all my questions. Thanks!

I would have almost thought it better to drain the engine oil totally before storage, only knowing that it won't be run for years..am I off base? Or would that have been the way with dino?

 

The guides were fine. The valves were sticking due to being held open by the camshaft, and sitting for so long. carbon build up and dino oil degradation caused them to stick in the guides.

According to the repair instructions, this 3.4 is listed as a zero-clearance motor. I will agree that after looking at the dishing of the pistons it does not appear to be so. I am just referencing what the repair manual for Mitchell1 says. If the book says so, I treat it as such.

Theory is sound in draining the oil if you allow it to sit for such a long time. My concern would be humidity and condensation. The oil will help collect naturally occurring condensation when it sits over time. This reduces the risk of rust. Again, not all of this is perfect. Some are just suggestions that I have learned over time. I have never personally dealt with having to leave a car sitting for more than a season.

 

I guess what e learned so far is draining is bettr than dino oil at least but do you think full synthetic would be better than a full drain

 

got any of that oil saved ? send for a UOA it would be damn interesting to get the report

 

Me too! O___o That's amazing. Subbed, btw.
My 96 Taco will probably look a lot like this, especially by the time I get around to rebuilding. The guy I bought it from back in August had let is sit since 2009. (maybe even 2008- the inspection sticker on it went bad November 09.) So I'll probably end up with something looking like this as well- I would hope not though, ha ha.
Me and my best friend are going to try to rebuild it, but depending on how it looks, I might just go out and buy a reman.

 

X2..