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Discussion Starter #1
Ok, i need a bit of help figuring out what exactly happened with my motor.

Short history:
I got a rebuilt motor to put in the car after an accident.

At the end of the break in (1000 miles nothing over 4000 RPM or 40% throttle) there was an issue with the passenger side cat getting clogged. My guess this had been happening for quite some time as when I took the cat off it was basically powder. The symptoms were that the temp got a bit hot on the highway (never past 95ish), and cooled down as soon as I pulled off. After a couple stops (checked coolant level/cap, verified fans were kicking on etc) the car had basically no power at all. So I got it home and gutted both cats. all was well again.

I was at the end of my 1000 mile break in, so I changed the oil and took it around the block... finally able to get it into boost. It pulled smooth and strong.

The next time I drove it was a warm day, but the temp stayed perfectly fine, but when I pulled of the highway at my destination the oil pressure light began to flicker, and I noticed a bit of smoke from the tailpipes.

I got it home and noticed the passenger side turbo had what looked like tar coming out of the cartridge, so I swapped it out with the one off the old motor, thinking that the heat from the melted cat had damaged it. No more smoking.

Now on to the oil pressure issue. I installed a gauge so I can see what the oil pressure ACTUALLY was doing. Upon start up it would be fine (40 psi), and would come down slowly as it warmed up to about 15psi. after idling for a long time (30-45 minutes) it would finally drop enough to trip the light, which comes on about 5 psi. Now if i started it up cold, and drove it (even easily) the oil pressure would drop to 5 or lower the first or second time I let it back down to idle.. even if i had only driven a block or 2.

I drianed the oil to put in a bit thicker mixture, and noticed a decent amount of metal (copper and aluminum) in the oil. I put in thicker oil and started it up and it acted exactly the same. I ran it for about 20 minutes until the oil pressure got to around 15 and drained the oil again.. it looked worse than the last oil.

So the motor is out and I pulled the pan off today, and here is what I found on the pickup. It looks and feels like some sort of film... slightly transparent, and brown in color. Along with some slivers of what looks like copper, and aluminum.






I pulled the oil pressure relief valve out found some pretty serious gouges on the piston.



Thoughts?

Thanks in advance.
 

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Did you replace th eoil coolers from the "accident" with the previous engine?

If the previous engine sent any metal particles into the oil coolers, they are very hard, if not impossible to clean out, and are technically supposed to be replaced.

No idea what those things are in your oil... Might be Loctite sealant?
 

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Discussion Starter #3
The oil coolers were re used, as the previous motor did not release any metal or coolant into the oil. I did "flush" them with with 2 quarts of the conventional oil I used for break in because the old oil had been sitting in the lines/coolers for over a year.
 

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Discussion Starter #5 (Edited)
The motor was done by very reputable Lotus tech Mike Sekinger, so it is EXTREMELY unlikely that this issue was an assembly problem.

The motor was doing wonderfully other wise. It wasnt until the cat clogged that the turbo let go, and then this issue arose. He said himself that the cat clogging couldn't affect the oiling system, but I'm wondering if that film is cooked oil from the turbo that got sent back into the pan.

Edit:
Just found this thread...
http://www.thelotusforums.com/forums/topic/4974-v8-oil-pressure-problem-solved/page__p__52079#entry52079
 

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Yeah I know Mike Sekinger, and have seen his engine rebuild threads on The Lotus Forums | News, Forums, Online Shop, Free Classifieds

The turbo also could have let go due to a blockage in the return line causing oil to blow out the seals. That blockage might have been that same goo.

I still don't have any idea what those copper strands could be.

The brown film does look like Loctite 518.
 

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I have read a lot of threads on rebuilt motors and I even know someone here in Houston that just had a rebuilt motor. I have yet to hear/read of one that didn't blow up within a 1000 miles. I guess if my motor goes, I am just going to part the car out instead of going down that rebuild money hole. :(
 

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My car sneezes
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"Flushing" the oil coolers with 2 qts does nothing. Capacity is more than that. You'd be surprized how quickly junk can get into the oil coolers.

Before you drop the motor again, pull the coolers and have them properly cleaned.
 

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My car sneezes
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I have read a lot of threads on rebuilt motors and I even know someone here in Houston that just had a rebuilt motor. I have yet to hear/read of one that didn't blow up within a 1000 miles. I guess if my motor goes, I am just going to part the car out instead of going down that rebuild money hole. :(
Why have these motors blown up?
 

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Discussion Starter #10
Yo Gonzalo

I plan to pull the coolers this time for sure. There was no reason (or so I thought) the last time because there was no bearing, or coolant contamination. I ran 2 quarts through with compressed air to try to get some of the old oil out of there. What is the capacity of the coolers and lines?

Im almost certain the issue with my motor rebuild was something caught in the oil pressure relief valve. looking at the gouge marks on the piston and I also just found some interesting wear marks on the inside of the piston and outside of the spring which I think points to it getting stuck open.

now heres the question... should i pull this all apart and replace the rings/bearings etc, or should I do like the old thread I found and just rebuild the oil pump?

There is no time frame on this project, but some life changes may not give too much money to dump into this in the next couple years, so an entire rebuild will probably end up a 5 year project. :(
 

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My car sneezes
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If your oil filter has no metal and you are positive the metal is from the relief valve and if your bearings look good, then just replace the front cover fron your old motor and call it a day.

Capacity for oil coolers and lines is a little over 2 qts but due to the location on the fittings, flushing doesnt work very well.
 

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My car sneezes
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It always seems to be some debris somewhere in the system that causes another failure.
I believe that. There are lots of places for dedris to get trapped.
 

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Discussion Starter #14
Gonzalo

So you suggest I pull off both the rod caps and main caps to inspect them, and then go from there?

I may shoot you some pics, or I can pay you in beer to come down and take a look yourself to help me make a decision.
 

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Discussion Starter #16
Cool man

Ill try to get it apart and ready to look at Sunday.. not sure if ill be around Monday until the evening, but ill let you know.

Thanks
 

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The copper and aluminum is coming from somewhere, most likely a spun bearing which is why you do not have oil pressure. The pressure valve is messed up from the contamination and could be sticking because of that also causing the oil pressure to be low. I would at the very least start pulling bearing caps but I think a full tear-down will be necessary because of the low oil pressure and all of the contamination in the oil. Once you get it apart it will be easier to figure the cause. It is either an assembly issue or a contamination issue. Cut the oil filter open. No matter how good any mechanic is, it is always possible he made a mistake or maybe it was a defective part. A full autopsy may reveal the truth. Depending on why and how the original motor failed you probably should have replaced the oil coolers or at least had them properly flushed. Read the plugs. Are they black from oil or too much fuel? I do not have a good answer as to why your cats failed unless you are pushing oil past the rings and fouled the cats. Is your exhaust pipe oily?
David Teitelbaum
 

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Have you checked out both your turbos?

Based on everything you've detailed, the evidence also suggests the possibility of a blown bearing / seal on one of the turbos.

The debris is consistent with the turbo shaft journal bearing material (copper, or actually bronze), and the other stuff may be chunks of the plastic / phenolic seal / housing ???

I don't know of any other place (other than maybe the small end rod bearings?) in the engine / mechanicals where you will find copper / bronze. The main engine bearings and big end rod bearings have copper in them but not in raw form like that, only in particle form impregnated into the base material --- so, when they shred, you don't see copper shavings like you have there.

Since the oil drain line from the turbo dumps directly into the sump, any debris from a damaged turbo bearing is going to be sucked up by the strainer (if it's small enough), immediately into the oil pump / relief plunger mechanism. And, once it's damaged, you will get a pressure loss.

Also, when oil can get past the shaft from a blown seal / bearing in the turbo cartridge, it can then get sucked into the intake side of the compressor or blown into the exhaust side turbine ---- either way, you will end up burning oil out the tail pipe.

Just a thought......just my $0.02.
 

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Discussion Starter #19
Could be that the turbo failed before the cat... I just dont know. The tail pipes were not oily, and there was no smoke before the cat melted. There was oil on the backing plate of the turbine wheel, and oil coming out of the compressor as well... which is why i changed it.

The drivers side turbo seems to be in good nic.

I had read somewhere that it is not uncommon to damage cats by running the red ecu, so i chalked it up to previous damage that finally let go.

The original motor ran well when i pulled it out. Its demise was an impact on the passenger side wheel which tweaked the motor/trans, and broke off one of the motor mount gussets above the oil filter housing. It was a clean break, but cut into oil passage ways which rendered the block useless.
 

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The original motor ran well when i pulled it out. Its demise was an impact on the passenger side wheel which tweaked the motor/trans, and broke off one of the motor mount gussets above the oil filter housing. It was a clean break, but cut into oil passage ways which rendered the block useless.
That's what got the "Pretty Woman" car. The stunt driver woman tapped the curb with the rear wheel and it turned out to be $20k+ in damage.




1998 Lotus Esprit V8
 
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