lamb chops

ive been seeing dropping oil pressure for the last couple of months on the cossie, i changed the oil to try and resolve it and put in silkoleane pro s but the oil pressure dropped further. it runs 45-50 psi when cold but drops to 15 psi on idle and 25 - 30 when running now.

I drove to our local meet last night and on the way i noticed vapor from the bonnet vent and shortly after i had a top end knocking so pulled over. opened the bonnet and vapor was coming out the spec R breather filter and a nasty tappet knock from the back of the engine, i opened the oil filer and the knocking stopped a little but shut it down. checked the oil level and it was half way up the dip stick.

The car has also been running hotter and when on idle the fans strugle to cool the engine and ive noticed the powdercoat on the rocker is blistering on the inlet side..

If the oil pump fails does it drop pressure like this or would it just die? I have a horrid feeling my engine is now in need of a rebuild I have a freind coming round next week to do a compression and leak down test but what do you guys think it sounds like?

I also have had an issue where i have lost power and have a real flat power curve, would the lack of oil pressure prevent the lifters from opening the valves fully hence the poor performance or is that bollox? Advancing the exhaust timing did give me a 30 bhp power increase on the dyno..

lamb chops

can see this turning in to a cossie breaking thread at this rate

fraser9764

iTrader: (3)

Noooo don't break it, yours is one of the nicest around IMHO, Best colour and best wheels
not too sure on cossie oil pumps but if lobes on the rotor bit or the actual casingwear then it can cause oil to pass and not create the pressure needed, i've heard of this happening on other cars but like i say, unsure on cossies but they are all pretty similar.
how old is the pump?

JamesH

iTrader: (21)

Take the dizzy out and check the hexagonal drive from that dizzy to the oil pump fo wear

We had oil pump ont he way out, and it was fine until the rev went above 3500-4000rpm and then the pressure dropped!!!!

Changed pump and shells out of course, and it has been spot on since, oh, and the old pump was FUCKED

Quite possible Re: lifters, very good point!

Best of luck

lamb chops

thanks for the replies guys, my drive to the pump could be shagged as the dizzy is very worn also and has quite a bit of movement in the shaft (have another being reconed now). Not sure how old the pump is.. if the leak down test and compression seems ok then i will replace the pump and check the crank etc for wear. Can you remove the sump with the engine in? I thought not but was told last night that you can remove the sump without dropping the cross member?? any ideas?

JamesH

iTrader: (21)

You can remove the sump with engine in, but I'm pretty sure you have to drop the cross member etc, may be wrong

I took the whole engine out and had it upside down, much easier, you cna see what you're doing cos the engines upside down, and not you!!

lamb chops

hehe good point James, just not sure ive got it in me to take the engine out again.. its only just gone back in!!

Ryan

tought luck mate

does sound bad mate, could be a worn pump, or worse, worn shell's now, decreasing oil presure only points to one thing really, the pump, so unless the spring has failed, i cant see it being anything else,

how old is the engine? your still on the original bottom end arent you?

sump cant be removed without the crossmember being dropped slightly or the engine lifted slightly as far as im aware, as you cant get the sump out from the pickup tube when everything is in situ.

Also regards the dizzy drive shaft, if its not working your fucked, there is no inbetween, either its working or its not, it can get worn, but if it goes past worn, the drive will no longer turn the pump, so that answers that.

Luca

iTrader: (2)

jOhn pull it out and rebuild it, speak to Dan and Russ there sort you im sure...

Jasesapphy

iTrader: (1)

Its a shit job droppping x member as you will also have to disconnevt the brakes as you have the copper lines that pass through the cross member so it will mean the brakes will need to be rebled, also you still are ristricted.

I did this job couple months back and i really think its easier just to pull the lump out.

On the brightside, i do have a genuine cossie 2wd high pressure pump i bought from Matt Lewis for Ł170 thats only done 200 miles i just need to get around to pulling the engine out

Ryan

as jase has said, we pulled my engine out to do my sump, much much easier and in all honesty, you can have it out 1 day, then back in the next no problems at all, if thats the only thing you plan to do.

lamb chops

not sure how old the engine is Ryan, its on a 200 block so has been rebuilt at some point. When i bought the car the guy said it had been rebuilt about 3k ago but dont have 1 recipt for the work so am taking that with a huge pinch of salt.

If i can make the summer out in it i would be happy as dont mind starting a rebuild project over the winter but to miss out on the show season for another year will be gutting. Dont have the funds to do quick rebuild at the mo so my best hope is to stick a new pump in and perhaps shells and trying to last the summer..

lamb chops

yeah think your right ryan engine out it the only way.. thanks for the advise Jase.

Will have a chat with russ and dan Luke good job i paid my outstanding debt last night haha

lamb chops

how much for the pump Jase?

rsnissan

iTrader: (9)

sounds like a nightmare mate! best bet as said is get it on the stand and just check everything on there.

rsnissan

iTrader: (9)

p.s remember to draw the line at pump and shells and dont get carried away doing other stuff while its out.

I ALWAYS fall for that one!!

lamb chops

thanks Andy, dont worry i wont mate

Luca

iTrader: (2)

John, get that pump then we can strip it down and send off for crank polish new bearings and check the pistons/block while apart.

New gasket set and your ready, dont be put off by ŁŁŁŁŁŁŁ to do it you will be surprised how much it wont cost...

Just tell the wife the food bill is more, well it is BBQ WEATHER after all.

Ryan

yes you do andy, your as bad as me.

But mine was purely cosmetic, where as yours if unecessary bufty mods

get the engine out tonight chops

lamb chops

ive just been out and started it from cold and the follower is still taping with 40-50 psi of oil pressure so that has gone without doubt. The funny thing is the oil pressure gauge reads 90 PSI for 10-20 secs when i start it and then drops down in stages as if its sticking.. im wonder if the gauge is screwed.. Need to try another before condeming the pump i think.. Does anyone have one spare

rsnissan

iTrader: (9)

what make is the gauge, is it mechanical?

lamb chops

its a mechanical revotech, only a cheap gauge

rsnissan

iTrader: (9)

yeah id deffo check that 1st make sure there are no leaks.

my SPA was dirty wiring BTW from when removing the head so that was Ł95 on a sensor for nothing

lamb chops

nightmare Andy, at least you have a spare now

How much is a set of followers for a cossie?

Ryan

about Ł70, not much mate

i have an electrical oil pressure guage if you want to test the pressure.

rsnissan

iTrader: (9)

cant remember but i have a set that fitted when i did the engine last time (now spare) so have done fuck all mileage if your interested

Luca

iTrader: (2)

Chopsie- with all the above your engine will brand new!

Now get it out.... OOOh er!

Jasesapphy

iTrader: (1)

get it out and check, best option, will pm you about the pump buddy,

Tappets are Ł70 for INA
Head Gaskets about Ł60 for Group A
Cossie big ends, little ends, thrust e.tc ACL Cossie are about Ł180
Sump gasket Ł20
and the pump

Job jobbed

lamb chops

great thanks guys what would i do without this place

Ryan how does the sensor for your oil pressure gauge attach?

Ryan

into where the standard oil pressure switch goes, with a takeoff section.

COCHYN

Get it sorted man, oil pump failure caused the loss of my car in total