Where is the pressure relief valve/ spring...

[chris1972]

... and what does it look like on the Serpentine engines? I've seen an image on the RV8 guide, but cannot see anything resembling that picture on my Chim on or around the oil filter/ pump area. Anybody got a photograph of one? Are there different types of pumps etc?

This is a shot of mine:

[v8 racing]

its just above the nut on the right hand side of the pic, held in with a circlip

[chris1972]

Thanks for the reply. I couldn't see anything. Is it set back?

[spend]

All your pictures from underneath are of no help really.

If you look from the front of the engine, you can see 2 horizontal galleries in the casting of the timing cover running from the crank c/l (oil pump) to the left (partially obscured by the damper). The lower one is the bypass feed pump-oil filter (the LR oil cooler blocks this off ~ which is what the 2 bungs are for... BTW) the upper one is the PRV bore. As they come out on the left the upper PRV one is about on the C/L of the oil pump and the lower bunged one extends further to the left.

[chris1972]

Okay cheers, I'll have another look!

[Sardonicus]

Just out of curiosity why?

[chris1972]

It is still taking a second or so for my oil pressure light to extinguish. I'd like to make sure I don't have a sticking spring (just part of the process) as I have read quite few stories on the net. I replaced my sump gasket recently, cleaned the pickup pipe from debris etc and cleaned the sump. Loads of oil pressure. I recently moved to an Ebay sender and am getting between 80-90+ lbs whilst driving and 60lbs on start-up on the gauge.

The only other thing I can think of is the switch for the pressure warning light. There is a switch/ sender that appears to have a weep, but I'm not sure what it is for. It is black and higher up the offside than the oil filter. Is this the oil pressure switch? If so, it is probably the weep that is causing the slight delay in extinguishing the warning light. I would attach a pic, but keep getting an Internal Server Error message from Thumbsnap, so have uploaded it here!

http://postimg.org/image/k2ap8dgmz/

[Sardonicus]

That oil pressure is wrong and unlikely to be PRV related get a proper sender on there, it should be 60 cold & hot idle 25/30 fast idle 55/60 approx that's what i get with a mechanical gauge and with the TVR gauge give or take a few PSI mine is not an Ebay sender by the way this pretty much mirrors other Serp cars I see I purchased mine form the classifieds on PH as I got fed up with mine under reading for the last 6 years

[chris1972]

I has one from the classifieds. It was good and then just stopped working.

The image of the switch I posted. Is that the pressure switch? I seeping a little, so I'd like to replace as it isn't too expensive.

[v8 racing]

If you havent found it yet the easiest way to see it is through the off side wheel arch, just turn the steering on lock and peer through

[chris1972]

I'll check it out, cheers for that.

Meanwhile, is this the pressure switch?

[v8 racing]

thats the oil light switch, the pressure switch (gauge) is at the front of the sump

[chris1972]

v8 racing said:

thats the oil light switch, the pressure switch (gauge) is at the front of the sump

Cheers. It seems to be leaking, so maybe time for a new seal.

[v8 racing]

more than likely the switch itself, about £5 from most suppliers

[Sardonicus]

chris1972 said:

I'll check it out, cheers for that.

Meanwhile, is this the pressure switch?

Hang on I am confused are you chasing oil pressure problems and a leak? only that oil switch in the last pic will not affect the gauge reading

[chris1972]

Nope, first of all, I was wanting to check the location of the relief spring. Secondly, I wanted to know if the last pic posted was the pressure switch for the oil light. Two different Q's.

Not to worried about the sender. I have good oil pressure. However, the oil light takes a couple of seconds to extinguish, hence wanting to ensure the relief spring wasn't sticking. However, on the face of it, it appears the switch for the oil light is leaking oil, which is more likely the cause for the delay in the oil light going out. I'll change the seal/ switch for the oil light.

Sorry if I confused matters, probably my loose terminology as I'm still climbing the learning curve!

[spend]

Losing a bit of oil from the oil pressure switch at the top of the timing cover isn't going to cause momentary low oil pressure at start up - sounds more like the switch is foobarred as previously mentioned. There are a few different switches for the RV8 that open at various pressures BTW but don't really worry too much.

I don't think your pump will be making 90psi so until the gauge pressure sensor is correct it would be a waste of time trying to work out whats going on (garbage in - garbage out adage), apart from fixing obvious leaks, worrying about faulty PRVs is a bit silly (as well as majority of interpubnet talk being about pre-serp PRVs BTW).

[chris1972]

Cheers for that. There seems to be a huge amount of conflicting opinion on here. Some swear by the Ebay senders, whilst others don't!

Eitherway, I do know, that until I changed the sender a couple of weeks ago, it was reading 30-45lbs on start-up and 45-60lbs driving. So if the new sender drops significantly from it's current readings I'll know that there is a problem.

The oil light takes about a second or so to go out after being stood. Not massive amount of time. Much quicker after being run. I'll try changing the oil light switch.

- Will any RV8 oil light switch do?
- Do you happen to know where I can get a new PRV for the Serp? I can't find one via Google.

Edited by chris1972 on Tuesday 16th April 12:34

[spend]

chris1972 said:

- Will any RV8 oil light switch do?
- Do you happen to know where I can get a new PRV for the Serp? I can't find one via Google.

Just about any RV8 switch will be fine.
You will struggle to find serp PRV stuff, as they are pretty much foolproof. Unlike the pre-serp you dont just unscrew them & pay a fortune for nothing to some bandit banging his drum about tadpoles to suit his wallet.... The serps have a seal so won't cause problems about the only thing you'd want to do is strengthen the spring or make them adjustable for VERY high revving engines. More likely failure @ PRV would be a problem with the timing cover itself (PRV bore) IMHO ~ hence replacement timing cover instead of PRV service IYSWIM.

You have probably been reading too much internet waffle about preserp oil pump & PRV and getting your knickers in a twist IMHO. Blind alleys & wild goose chases spring to mind?

[chris1972]

Okay, cheers for that! The internet is the source of doom and gloom sometimes!

I'm not too concerned and think it is something simple to be honest. No sooner do I start it up, the pressure gauge starts climbing. New oil pump fitted 3 years/ 7k miles ago.

Thanks for your help. Appreciated.