What is this engine component?

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What is this engine component?

February 27, 2021, 05:28:13 pm

There seems to be an oil drip from this part in the engine bay. What is this part and what might cause the drip?

Re: What is this engine component?

Reply #1 – February 27, 2021, 05:34:30 pm

That's the belt tensioner and I don't see how it should leak. It's just sealed bearings in it. Clean off the area and see it is coming
from somewhere else.

Re: What is this engine component?

Reply #2 – February 27, 2021, 05:39:58 pm

That is the belt tensioner. It does not have any oil in it but the oil may be coming from a seal on the pump on the left in the photo or could be blowing back from the engine. Does any oil drip on the ground when you park it? Best would be to clean the area and then look closely for where the oil might be coming from.

Pierce

Re: What is this engine component?

Reply #3 – February 27, 2021, 06:10:37 pm

Looks like the oil is coming from behind the pump pulley. meaning the seal there is probably leaking.

Re: What is this engine component?

Reply #4 – February 27, 2021, 07:58:12 pm

Yup, hydraulic pump main shaft seal.

Re: What is this engine component?

Reply #5 – February 27, 2021, 08:08:36 pm

Quote from: wolfe10 – February 27, 2021, 07:58:12 pm

Yup, hydraulic pump main shaft seal.

Okay so where in these pics is the hydraulic pump? Behind the bigger wheel to the left of the tensioner? And that wheel would connect to the end of the pump main shaft?

Re: What is this engine component?

Reply #6 – February 27, 2021, 08:37:42 pm

Quote from: Dan & Annie – February 27, 2021, 08:08:36 pm

Okay so where in these pics is the hydraulic pump? Behind the bigger wheel to the left of the tensioner? And that wheel would connect to the end of the pump main shaft?

Yes, to both. The pump mounts to the plate behind the pulley, and the pump shaft sticks through the mounting plate. The big fabric covered hose (in right photo) above the pulley is probably the pump supply hose from the hydraulic reservoir (big round black tank with a dip stick in the lid). Since you are leaking some hydraulic fluid, you might want to check the oil level in the tank.

The hydraulic pump provides the oil pressure that drives your engine cooling fan motors, so it is rather important.

Re: What is this engine component?

Reply #7 – February 27, 2021, 08:55:42 pm

It also provides power steering on my '03.

Re: What is this engine component?

Reply #8 – February 27, 2021, 08:58:17 pm

I enlarged the photo and looked above where the puddle was and saw this on the filter. Could that possibly be the leak?

Dan&Anne
Is there anything wet on the bottom of the coolant filter?

Re: What is this engine component?

Reply #9 – February 27, 2021, 09:14:30 pm

Quote from: master2301 – February 27, 2021, 08:58:17 pm

I enlarged the photo and looked above where the puddle was and saw this on the filter. Could that possibly be the leak?

No if that was the leak the alternator would have oil on it. Look at you first picture and you can see the dark area behind the pump pulley.

Re: What is this engine component?

Reply #10 – February 27, 2021, 09:55:09 pm

That's a coolant filter.

Re: What is this engine component?

Reply #11 – February 27, 2021, 10:09:53 pm

Looks like a seep rather than much of a leak. If it is, an additive may do the job. Much of a leak would show up on the ground.

Pierce

Re: What is this engine component?

Reply #12 – February 28, 2021, 01:06:32 am

If it is in fact the hydraulic pump, you might try some Lucas Hydraulic Oil treatment. Ours was seeping a little and now it isn't.

Drain the 15/40 oil out of the pump reservoir , clean the filters refill with 15/40 and some Lucas. Might help.

Re: What is this engine component?

Reply #13 – February 28, 2021, 06:59:52 am

Thanks for all the help on this, folks. Here's some more background.
I bought this coach from MOT in June. My first trip, 600 miles, no leak. Second trip, 1,100 miles. First 1,000 - no leak. When I went to unhook the toad after the last 100 miles, it was covered in oil (or some kind of fluid) that wasn't there 100 miles ago. Bumper, trailer hitch, and inside of the coach engine compartment covered in oil. I was able to pressure wash it all off, dry it all up, nice and clean. This was back in November. Since then I have made a few short drives of 10-20 miles each, trying to see where this came from, but found nothing leaking. Last month did a 400 mile trip, again with no leaks, other than what we see in the pics posted earlier.
I was planning to leave today on a 1,200 mile trip. What's your advice on what I should check before I go, and what to watch for during my trip?

Re: What is this engine component?

Reply #14 – February 28, 2021, 07:51:20 am

Quote from: Dan & Annie – February 28, 2021, 06:59:52 am

What's your advice on what I should check before I go, and what to watch for during my trip?

Hard to fix a leak, when you don't know what is broke. You are on the right track - just haven't pinpointed the problem, yet.

Two possible sources of errant oil in the engine compartment: engine crankcase oil and the hydraulic system.

On the trip where you had the big oily mess, is it possible you (or someone else) could have over filled the engine oil (crankcase)? If there is too much oil in the engine, it will be expelled out the breather tube. This oil will blow all over the engine compartment (and your tow car). This will continue until the excess oil is dumped, then it will stop.

The hydraulic system is a big closed loop. From the reservoir, to the pump, to the fan motors and possibly the power steering box (up front), and then back to the reservoir. Many feet of hose. The whole loop is under high pressure. A leak could occur anywhere.

The usual suspects are the pump front shaft seal, the shaft seals on the hydraulic fan motors, and the hoses. The shaft seals start out slow by seeping a tiny bit of oil. This may continue for years/thousands of miles before requiring serious attention. Not usually a emergency.

A leak in a hose, on the other hand, can strand you on the side of the road depending on its severity. Hose leaks can result from either physical damage (a piece of road junk bounces up and slices a hose) or from abrasion. A hose rubbing on another hose or a piece of metal can slowly wear a hole through the outer protective cover. When it finally lets go, it could be a serious blowout dumping gallons of oil in seconds.

Your leak is rather puzzling, since it seems to come and go. All you can do is keep searching until you determine the source. Then fix it.

Re: What is this engine component?

Reply #15 – February 28, 2021, 08:16:33 am

Quote from: Bob & Sue – February 28, 2021, 01:06:32 am

If it is in fact the hydraulic pump, you might try some Lucas Hydraulic Oil treatment. Ours was seeping a little and now it isn't.
Drain the 15/40 oil out of the pump reservoir, clean the filters, refill with 15/40 and some Lucas. Might help.

I am pretty sure that Robert meant to say "Replace the filter(s)".

Re: What is this engine component?

Reply #16 – February 28, 2021, 08:30:40 am

I just went out and wiped clean everything I could see. I agree now that the seal for the hydraulic pump shaft is likely the issue. The flat cover of the box under the crank pulley was wet all the way up to the shaft. Like I said I dried it up and will keep an eye on it throughout this upcoming trip. The fluid in the reservoir was just a 1/4" below the full mark on the dipstick, with engine cold and not running.
It's possible engine oil was overfilled when MOT did their pre-sale inspection/maintenance, but odd that I drove it 1,500 miles before having this big blow out.

Re: What is this engine component?

Reply #17 – February 28, 2021, 08:31:33 am

Start by completely cleaning the area so you can identify the source of the leak. Moving parts and air flow tend to spread a leak from it's source, making it somewhat difficult to determine the actual source.

Also, identify the fluid. If hydraulic oil it will be clean/clear 15-40 motor oil. If a leak from the engine it will be blacker. Coolant will smell-- well, like coolant.

Posted while you wrote your last post. No, overfilling the reservoir would not cause a leak. BTW, what is the fluid level in the hydraulic reservoir?

Re: What is this engine component?

Reply #18 – February 28, 2021, 08:35:39 am

Quote from: Dan & Annie – February 28, 2021, 08:30:40 am

It's possible engine oil was overfilled when MOT did their pre-sale inspection/maintenance, but odd that I drove it 1,500 miles before having this big blow out.

Agree this would not be logical. Over-filled engine crankcase would start expelling oil immediately. It would not wait 1,500 miles.

Re: What is this engine component?

Reply #19 – February 28, 2021, 08:45:18 am

Quote from: Dan & Annie – February 28, 2021, 06:59:52 am

first trip, 600 miles, no leak. Second trip, 1,100 miles. First 1,000 - no leak. When I went to unhook the toad after the last 100 miles, it was covered in oil (or some kind of fluid) that wasn't there 100 miles ago. Bumper, trailer hitch, and inside of the coach engine compartment covered in oil.

Quote from: wolfe10 – February 28, 2021, 08:31:33 am

Also, identify the fluid. If hydraulic oil it will be clean 15-40 motor oil. If a leak from the engine it will be blacker. Coolant will smell-- well, like coolant.

Yes - do you recall what the initial oil leak looked like?

I'm sure you've checked, but the one time we had this experience of oil all over the engine compartment, toad, etc., the oil fill cap had been left off after an oil change. We found the cap (it was on the side "shelf" in the engine compartment), replaced it, and cleaned everything up. Dipstick-wise, we hadn't lost much oil, but it sure made a mess! Of course, a scenario like this would have manifested early on (unless the issue was a cap that wasn't tightened down, and came loose over time).

Another issue that has affected some is abrasion of the line to the hydraulic filter - if the housing isn't oriented "just so", the hose can rub on the engine bay door.

Re: What is this engine component?

Reply #20 – February 28, 2021, 09:08:47 am

The big blowup was back in November, and I just just assumed it was engine oil and cleaned it up. Didn't think about hydraulic fluid at the time, but I was expecting it would show up again as soon as I drove a few (hundred?) miles.
Everything is clean now and both engine oil and hydraulic fluids are full (still full, I haven't topped anything off.)
Will report back later today after we stop for the night. 300 miles up to Valdosta, GA.

Re: What is this engine component?

Reply #21 – February 28, 2021, 11:20:04 am

On top of the engine valve cover is the breather hose,it travels down to the engine oil pan level and goes to atmoshere,it's possible this could be plugged or restricted and causing an engine leak.

Re: What is this engine component?

Reply #22 – February 28, 2021, 08:18:28 pm

Here's what I've got after 300 miles. Not so bad.

Re: What is this engine component?

Reply #23 – February 28, 2021, 08:26:41 pm

That's a small seep. That would be normal for one day's riding on an old BSA or Triumph motorcycle. Use a chemical seal expander to soften and expand the seal. Follow the directions for the amount you will need.

Pierce

Re: What is this engine component?

Reply #24 – February 28, 2021, 10:38:44 pm

Pierce,
Can't let that knock on British bikes go unanswered, one of the ways to check oil volume in a Harley Ferguson was to look at the ground underneath, no oil puddle then the motor is low.

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